Hi Gents !!! I think you would be better buying the whole L6 light, because just the KL6 head runs like $160. For another $70, you get the L6 body, and the awesome Z58 clickie, lanyard and box !!! I just put a KL6 head on a brand new SF M900a weapons light for my AR-15, and sold the L6 body and Z58 clickie to a forumite, bringing my KL6 head cost down to around $110...