A mount to secure headset control module.  Plastic is UV resistant. For type, "Flange" is the one with screw locators on each side and "No Flange" is recommended to be mounted with 3M Dual Lock.   The price is for one part.  If you need both pilot and copilot side then order two.    Also fits Zulu 2. 
 
If Delta Zulu, click here.