Some shimming may be required depending on the application (Shims sold separately.)
This mounting bracket allows you to mount a taillight in different positions on your recumbent (chain stay, seat stay, seat frame, etc.) The XL size also works great as a cadence sensor mount for your computer on the front derailleur mast.
X-Large: Fits 28.6-31.8mm or 1/1/8-1 1/4 inch tubes.
Upper Volae seat stay measures 12.7mm, lower seat stay measures 16.5mm and chainstay (mid measurement) 27.1mm.