CP Gear Tactical has a new ruck out. The new 64 Multi-Frame pack is based on the Canadian Army ‘64 Rucksack’, based by the Canadian Army on the US Army’s Vietnam era T62-1 Lightweight Rucksack. The pack itself (obviously significantly modernized), hip pad, yoke and shoulder straps can be attached to any of five different frames. The pack has an optional nylon pack liner (held in place with hook-and-loop tabs and is made of 1000d Cordura in CADPAT pattern camouflage. It’s MOLLE compatible and designed to accommodate Canadian Forces issue CTS buttpack and 2 CTS pack pouches.
They have a video showing all the features and explaining how it works:
(You can see if your frame will fit in a drop-down box on the Components section of the web page for the ruck—on that page you can select a frame or ruck set-up, or purchase the ruck by itself if you already have shoulder straps and frame.)