The PB after market clip its the easiest solution. Pretty cheesy that PB doesn't include this item in the package with the light. I haven't had one bike where light would clamp in a manner that would not result in losing the light in the middle of the road at about 4:15 a.m. seems like the seat stays on my bikes were not large enough diameter to work with the supplied item without a bunch of shims and another length screw so I bought the clip but next time I need to I'm going to make one.