Integral Stack Lock A purpose-built latch to secure full Packout organizer stacks. The spring-loaded system accepts any Packout organizer with rails. Attach and detach within seconds. Secures and stabilizes any Packout with side rails. Two Versions: Unistrut and E-Track mount options available. Please select the correct version below. Unistrut Design: Compatible with Unistrut or other universal rail systems. 1-5/8" width Unistrut is required with a minimum length of 26.25". Any depth is okay. 26.25" of Unistrut length is required per locking kit. Comes with track nuts to attach the locks to the Unistrut. Unistrut is not included and must be purchased separately. E-Track Design: Attaches directly to E-Track. Spacers are included to mount any Packout configuration. E-Track is not included and must be purchased separately. Secure Stacks: Perfect for outfitting a full wall in a trailer, van, etc. Larger sections of unistrut can be purchased separately to attach this mechanism. Features Secures any Milwaukee Packout Organizer with aluminum side rails. Powder-coated aluminum parts. Rust-resistant, coated hardware. All hardware is included (Unistrut & E-Track sections not included) Fitment Fits and locks all full-size Milwaukee Packout organizers with aluminum rails on the sides. The included track nuts work with standard 1-5/8" Unistrut. Any depth is okay. It could be mounted universally to various flat, level surfaces or other rail systems. Installation instructions can be seen here: Unistrut and E-Track Patent Pending Utility patent pending.