SKU: 202363 Categories: ,

The ATOM Chest Harness provides exceptional comfort and versatility for high angle rescues. The ATOM Chest transforms the ATOM Sit Harness or Build Your Own (BYO) ATOM Sit Harness into a full body NFPA Class III Life Safety Harness. This modular unit is quickly and easily assembled for team members who transition from working on the edge to working on the rope. It allows rescuers to utilize the mobility of a sit harness until the comfort and versatility of a full body harness is desired. Use the ATOM Chest when the job calls for hanging on the rope, managing heavy loads, and operating complex rope systems. Compatible with CMC’s Chest Ascender Kit and built with multiple steel attachment points, the ATOM Chest delivers safety, comfort, and next-level versatility for the rope technician.


Transforms ATOM Sit or Build Your Own (BYO) ATOM Sit into a NFPA Class III Life Safety Harness.

Allows teams to utilize the mobility of a sit harness until a full body unit is preferred for working on rope.

Sternal and dorsal steel D-rings provide robust, low-profile attachment points that can fit multiple carabiners.

Integrated load transfer from chest attachment points to the Sit Harness, increasing comfort in a vertical lift.

Compatible with a variety of chest ascenders that can be added or swapped using the ATOM Chest Ascender Kit.

Built for all-day comfort and security, while being quick to install or remove to meet the demands of the job.

Constructed using water-repellant, UV resistant webbing, as well as breathable D3 cloth in the dorsal padding.

Available in black with contrasting thread for wear inspection and Black Web Keepers™ to secure loose ends.

Replaces the ProSeries Chest Harness and adds another level of customization to the ATOM Harness Series.


The current ATOM Sit and BYO ATOM Sit (PN# 202B) has a rear oval ring for attaching the ATOM Chest. This combination creates an NFPA Class III Life Safety Harness without the need for additional hardware.

The previous ATOM Sit (PN# 202A) has a soft loop on the back. A Trapezium Quick-Link is required to attach the rear tether of the ATOM Chest to the ATOM Sit. This combination is not NFPA Class III, but the ATOM Sit retains its NFPA Class II designation.


To combine the ATOM Chest with the ATOM Sit or BYO ATOM Sit, follow these steps and refer to the Pro Tip Video.

1) Remove the dorsal webbing from the slider buckle.

2) Feed the dorsal strap through the oval ring (202B) or Trapezium Quick-Link (202A) on the back of the ATOM Sit.

3) Re-attach the dorsal strap to the slider buckle of the ATOM Chest.

4) Feed the trap link through the center loop on the ATOM sit. Make sure it feeds through all of the webbing layers.

5) Tighten the trap link using a 15mm wrench.


To install or swap out a variety of chest ascenders, follow these steps and refer to the Pro Tip Video.

1) Open the trap link on the ATOM Chest and remove the front lift.

2) Run the chest ascender strap loop over the front lift of the ATOM Chest.

3) Push the stiffened end of the chest ascender strap through the top hole of the chest ascender and over the back of the front lift.

4) Push the stiffened end under the top strap, over and back under the bottom strap, and under the chest ascender strap loop itself.

5) Reconnect the front lift to the trap link and tighten with a 15mm wrench.

6) Use the delta link to connect the chest ascender to the atom Sit ventral webbing attachment point.

7) Confirm the delta link is positioned in front of the ATOM Chest trap link, running through the same webbing loops.

8) Tighten the delta link with a 14mm wrench. Both the delta and trap link should be secured a quarter turn beyond hand tightness.



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