The frame is a large plastic exoskeleton, which follows the rear circumference of the pack, connects up to the Flink ball joint with a cross member, and has a bottom pan that cradles the pack, and finishes with two long tongues that slide into each side of the hip belt. The Flink ball joint is unique, as the shoulder harness not only freely rotates in a spherical direction (though it does have some stops), but it’s also free floating, meaning it’s only attached to the ball joint and is therefore, isolated from the frame and pack. The ball itself, which is just a half of a sphere, rotates in the frame’s socket, and is attached with a single large bolt. I never had any issues with the singular bolt, but it does mean a single point of failure in the grand scheme of things.
The pack comes in two sizes, regular (which I tested) and large, and the size is chosen by a height range. Regular is for heights between 5’1″-5’11″, while large is for those between 5’9″-6’5″. Each of the sizes has three back length adjustment settings for varying torso’s (small, medium and large), and are adjusted by moving the Flink ball joint onto one of the accompanying slots in the frame of the shoulder harness. Once the proper position is located, a bolt comes through the back of the shoulder harness, through the ball and threads into the socket. You can adjust the firmness of the ball and socket, by the amount of torque you apply to the bolt. There is a nice instruction booklet, and a label inside the pack that gives detailed information into the procedure. I set the connection to the lowest slot, or large setting, since I was towards the maximum torso length (5’9″) for the regular frame size.