I have both the solo and dual Corbin seats. The dual does not use a key/lock and mine fits perfectly on the CVO using the existing mounting points. I'm very pleased with the fit and finish of this saddle. The solo locks onto a new front mount that must be installed, and requires the additional rear mount bracket. Thus these two pieces must be removed to switch to the dual, which is a bit annoying but actually takes little time. I did not bend the rear bracket to fit the fender curve but rather added a strip of 1/8" nylon belting underneath the bracket. I still do not fully understand the rear bracket on the solo in as much as the rear of the saddle is not attached in any way. The saddle can move vertically a small amount and essentially slides into the cutout of the rear bracket. Maybe Corbin thought this movement increases comfort or absorbs shocks in some way?