A mount to secure headset control module. Plastic material type is ASA that is UV resistant and NOT biodegradeable PLA like some others. For type, "Flange" is the one with screw locators on each side and "No Flange" is the one that you put velcro on. (Velcro not included). It is a very good fit. Approved for aerobatics but easy to remove. The price is for one part. If you need both pilot and copilot side then order two. It has a good sturdy base. Also fits Zulu 2.