The Chrosziel FGV 7D Shoulder Support Kit 2 is a DSLR rig that's specifically designed to accommodate retrofitted Canon EOS 7D cameras outfitted with a PL mount by FGV Schmidle. At its center is the Lightweight Support that offers a proper riser for the retrofitted 7D.
The kit also includes a pair of Chrosziel AC-403-10 Handgrips, which attach to the Lightweight Support's standard 15mm rods, and a DV Balancer with Belly Rest. That piece is a shoulder pad / torso brace assembly that attaches to the back of the lightweight support. All told, the FGV 7D Shoulder Support Kit 2 gives you four points of contact with the rig, engendering the maximum amount of stability you can achieve from shoulder-mounted operation. You can achieve balance with just the shoulder pad and belly rest pressing against your body, while your hands attend to camera settings, for instance.
The Lightweight Support's 15mm rods can accept a follow focus and/or a matte box – the camera riser has put the retrofitted 7D at the proper level to attach these accessories to your PL mount lens. All the parts of the kit, of course, are modular and adjustable, so if you want to remove, for example, the belly rest or the shoulder pad, it's a simple matter of twisting a thumbscrew.