The AO-8T is designed for the STT Camera Series. It requires the FW8G-STT Filter Wheel or STT Remote Guide Head and OAG to operate the AO-8T. This is the same AO as the model AO-8 with a different back plate to match the STT Camera series hole patters. If you already have an AO-8, it can be converted to an AO-8T by changing just the back plate. Contact our Customer Serivce for this modification.