This is The Collitron Reticle product choice when ordering and NOT adding to your Binotron 27 order. Note that the threads are specifically for Binotron 27 Binoviewers. While this reticle may fit other brands of binoviewers with specially made adapters and it may function properly, we do not warranty or guarantee this product when used with used Denkmeier Binoviewerrs or other brands of binoviewers..