Back-Bone Adapter Canon EOS to C-Mount This filter kit includes a

This filter kit includes a circular polarizer

but for best result

This part is designed to fit into the cylindrical bore wall of fork stems and will work with stems that measure from 12 -20mm and 28mm or

Ultra tight on helmets

camera motor noise

Back-Bone Adapter Canon EOS to C-Mount This filter kit includes aConnect your favorite manual Canon EF lenses to your Ribcage with this EOS to C Mount adapter. Fully automatic lenses can also be connected but please note that there is no electrical connection via C Mount, so auto focus and iris settings will not function. Fully automatic EOS lenses default to having the iris wide open when used with this adapter. 35mm (full frame) lenses will experience a crop factor of 5. 7 with the Ribcage.