Spiritus Systems Fat Strap Mk4

Spiritus Systems Fat Strap MK4 – Tactical Chest Rig H-Harness

Streamlined. Modular. Mission-Ready.
The Fat Strap MK4 is the next evolution of Spiritus Systems’ universal H-harness, engineered to integrate seamlessly with the Micro Fight Chassis, 34A Split Chest Rig, and Thing 2 expansion chassis. This rugged, no-nonsense design cuts out the fluff and delivers just what you need: comfort, compatibility, and customization—without the bulk.

Crafted with a Squadron overlay panel, the MK4 provides increased horizontal real estate for PTTs, comms gear, shock cord attachments, and more. A loop field on the rear allows for name tape or IR marker placement. It’s built with Spiritus’ Brilliance in the Basics mindset—so no complicated yoke systems or gimmicks, just gear that works.

Why We Love It:

The Fat Strap MK4 is a minimalist powerhouse—no over-engineering, no extra weight. It does exactly what it needs to do and nothing more. Perfect for streamlined chest rig builds and rugged field use.

The Fat Strap MK4 is a single strap. You do NOT need to order two to complete your Micro Fight or 34A Split Chest Rig. You only need to order ONE. 

NOTE: The FAT STRAP is part of the Spiritus Systems Micro Fight and 34A Chest Rig Systems. This item does not include the chassis, back strap, magazine inserts, or any other accessories. 

Some images are shown with optional accessories, sold separately.