Thats the Cloverleaf 5.8G antenna covers (compatible for 90 degree adaptor).
I bought a pair of cloverleaf 5.8G antennas from the shop and found the product itself with cover is more then double. Therefore, I made the pair of the covers for my antenna.
This package include 2 cover (TX and RX)!
Also, this size is only fit for 5.8G. 2.4G and 1.2G does not fit. Please note.
Cloverleaf 5.8G antenna cover (compatible for 90 degree adaptor) by brianhomer,
available under a
Creative Commons - Attribution license.