AirCore Harness with Aluminum Hardware
The ACA is the lightest AirCore: the open-core breathable padding and DuraFlex stretch webbing carried on lightweight aluminum hardware, with quick connect buckles at the chest and legs. For workers who count every ounce across a ten-hour shift, this is the top of the breathable line.
Rated for a 400 lb weight capacity and listed by the manufacturer as meeting OSHA, ANSI, and CSA fall protection standards, AirCore is the breathable premium line of the Miller range, built for workers who live in a harness.
Miller Harness Sizing Chart
Height (ft) by Weight (lb)
| 110 | 130 | 150 | 170 | 190 | 210 | 230 | 250 | 270 | 290 | 310 | 330 | 350 | 370 | 390 | 400 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 6′6″ | ||||||||||||||||
| 6′4″ | XXL/XXXL | |||||||||||||||
| 6′2″ | ||||||||||||||||
| 6′ | ||||||||||||||||
| 5′10″ | UNIVERSALMost Popular Size (L/XL) | |||||||||||||||
| 5′8″ | ||||||||||||||||
| 5′6″ | ||||||||||||||||
| 5′4″ | ||||||||||||||||
| 5′2″ | S/M | |||||||||||||||
| 5′ |
S/M fits workers up to 5 ft 10 in and 170 lb, or up to 190 lb at 5 ft 6 in and under. Universal (L/XL) covers the broad middle and is the most popular size. XXL/XXXL fits workers over 6 ft who weigh over 270 lb, and any worker from 350 to 400 lb. Lighter boundary bands are overlap zones where either size fits: size down for a trim fit or up for room over layers. Some Miller spec sheets list these as Size 1 (S/M), Size 2 Universal (L/XL), and Size 3 (2XL and 3XL). Based on the manufacturer's published Miller sizing chart; verify fit per the user manual before first use.
Who Needs This Product
The aluminum AirCore is for the worker who wears a harness more hours than boots: tower techs, inspectors, and full-time at-height trades where padding, stretch webbing, and hardware weight all compound over the day. This is the green Universal (L/XL) size.
Features
Lightweight Aluminum Hardware
Aluminum D-ring and buckles carry the same certification as steel at a fraction of the weight, cutting shoulder fatigue on all-day wear.
AirCore Open-Core Padding
Breathable open-core padding channels air across the back and shoulders, keeping workers drier and cooler than solid-pad designs.
DuraFlex Stretch Webbing
Patented stretchable webbing flexes with every reach and crouch, delivering the mobility AirCore is known for.
Stand-Up Back D-Ring
The dorsal D-ring stands up on its own, so connecting an SRL or lanyard is a one-hand reach instead of a blind fumble.
Cam Shoulder Buckles
Cam buckles on the shoulder straps give fast, fine torso adjustment that holds its setting under load.
Knitted Mesh Back Shield
The mesh shield sheds moisture and keeps air circulating between the harness and the worker.
Technical Specifications
| SKU | ACA-QC/UGN |
|---|---|
| Product | AirCore Premium Breathable Full Body Harness |
| Sizes | Universal (L/XL) |
| Color | Green |
| D-rings | Stand-up dorsal (back), aluminum |
| Chest buckle | Quick connect |
| Leg buckles | Quick connect |
| Adjustment points | 5 (chest, shoulders, legs) |
| Webbing | Patented DuraFlex stretch polyester |
| Padding | AirCore breathable open-core padding with knitted mesh back shield |
| Weight capacity | 400 lb / 181 kg including all clothing, tools, and equipment |
| Packaging | Bagged each |
| Country of origin | Mexico |
| Standards | ANSI Z359.11; OSHA 1926.502; OSHA 1910.140; CSA Z259.10; TAA compliant |
| Warranty | Miller Limited Lifetime Warranty against defects in workmanship and materials |
Fit before the first step up. Set the cam shoulder buckles so the stand-up dorsal D-ring sits between the shoulder blades, the chest strap crosses mid-chest, and the leg straps allow a flat hand but not a fist. A harness that has arrested a fall is done: remove it from service immediately.
Compliance Standards
ANSI Z359.11
Certified to the ANSI/ASSE Z359.11 standard for full body harnesses, covering design, testing, and marking requirements.
OSHA 1926.502 and 1910.140
Meets OSHA requirements for personal fall arrest system body wear in both construction and general industry.
CSA Z259.10
Certified to CSA Z259.10 for full body harnesses, marked for use on Canadian jobsites.
TAA Compliant
Listed as TAA compliant by the manufacturer, allowing purchase on federal projects that require Trade Agreements Act sourcing.
Typical Applications
Donning Overview
- Hold the harness by the back D-ring and shake it out so the straps hang free without twists.
- Slip the shoulder straps on like a vest, keeping the webbing flat against the body.
- Connect the chest buckle and position the chest strap across the middle of the chest.
- Fasten each leg buckle so the strap allows a flat hand between the strap and the leg, but not a fist.
- Work through all five adjustment points until the dorsal D-ring rests between the shoulder blades, then stow the strap ends.
Full donning and adjustment instructions are in the Miller harness manual linked in the documentation section below.
Inspection and Retirement
Inspect this harness before each use, and have a competent person other than the user formally inspect it at least annually per ANSI Z359.2. Check each point below and record the results on the inspection form linked in the documentation section.
- Webbing: cuts, frays, burns, chemical damage, UV fading, or broken stitching anywhere on the harness.
- Hardware: D-rings and buckles for cracks, corrosion, distortion, or sharp edges.
- Adjusters and keepers: slippage, missing keepers, or strap ends that will not stay stowed.
- Labels: present and legible, including the size, standards, and serial information.
Retirement triggers: any fall arrest event, any webbing or hardware defect found during inspection, or any condition where the inspector cannot positively verify the harness is fit for service.
Fall ProtectionDistributors, LLC Free Tool · No Signup · OSHA 1926.502 Free Interactive Tool Fall Protection Calculator Pick your system. Run the math. Generate a plan. 1Pick Your SystemDetermine fall restraint vs. fall arrest based on your work surface, edge access, and clearance. 2Run the MathCalculate exact fall clearance required below the work surface for your SRL or lanyard setup. 3Generate a PlanGet a printable OSHA-compliant Fall Protection Plan structured around 29 CFR 1926.502(k).
Frequently Asked Questions
Miller ACA-QC AirCore Harness Submittals and Documentation
ACA-QC Specification Sheet (PDF)Technical data, sizing, materials, and SKU-level UPC information. ACA-QC User Instruction Manual (PDF)Miller I119 manual: donning, adjustment, use limitations, and inspection criteria. Miller Fall Protection Catalog (PDF)The full Miller line: body wear, connecting devices, anchors, and rescue. ACA-QC Harness Inspection Form (PDF)Printable pass/fail checklist for documented harness inspections.Compatible and Related Products
- Miller H700 Premium Harness, Back D-Ring. The 3D-padded premium alternative with trauma relief steps.
- Guardian CR5 Class 1 Single Leg Web SRL, 6 ft. A compact web SRL to pair with the stand-up dorsal D-ring.
- Guardian 10733 Suspension Trauma Strap, 4-Pack. Add a trauma relief strap to every harness on the crew.
Outfitting a Crew with Breathable Harnesses?
Hardware, D-ring layout, color, and sizing decide the right AirCore. Confirm your crew with us and we will make sure the right equipment ships together, based on the delivery location.
Call 863-703-4522 to talk to a fall protection specialist.
Miller Limited Lifetime Warranty
Miller Fall Protection products are covered by the Miller Limited Lifetime Warranty. In the manufacturer's words: "We sincerely believe that our fall protection equipment is the best in the world. Our products endure rigorous tests to ensure that the fall protection equipment you trust is manufactured to the highest standards. Miller fall protection products are tested to withstand normal wear and tear, but are not indestructible and can be damaged by misuse."
In the unlikely event that you should discover defects in either workmanship or materials, under the Limited Lifetime Warranty, Miller will repair or replace the product at the manufacturer's expense. If a replacement is necessary and your product is no longer available, a comparable product will be substituted. The Limited Lifetime Warranty does not apply to normal wear and tear or abusive treatment of the product.
Miller is a brand of Protective Industrial Products, Inc. (PIP). Should a product issue surface, contact Fall Protection Distributors, LLC and we will coordinate the warranty claim with the manufacturer.
