Hepco & Becker have produced the Tool Tube as a kit for all cutout case frame sets.  We also have the "generic" tool tube 741000 that can be fitted to any frame or location.  The main point in self-mounting off one of our pannier frames for most bikes is that there is clearance for the chain guide with the suspension in full compression.  We suggested to one of our CRF1000L Africa Twin customers that a 16mm single saddle (eg most hardware) and an L bracket bolted behind case tabs would work and he has done a fine job.  If you don't run hard case on your frames eg you run our Monsoon soft bags, then the tube can sit up against the frame tube on the inside.  But if you run our hard cases then you need to allow ~ 20mm clearance when the case is inserted. It is all do-able but up to you to mount the tube firmly & ensure the clearance.  

• Inside dimensions: 29x8 cm (length / diameter)
• Outer dimensions: 32x9 cm
• Volume: 1.5 litres