I purchased one from B-Square a few years ago. It connected to the gun where the front and rear sight does. It worked great but I think it effected the accuracy a little. For hunting at 100 yards it was good. There are numerous mounts available that connect to the dove tail slots where the rings clamp.
I ended up moving my holosight to a BFR for hunting and putting the scope rings back on the SRH for targets.
Jerry