as of recent those parts are not sold to the end user. I had to repair both my rtk and non rtk h520e with antenna lens coming off from the arms. had to send in both units to webster new york for repairs. for my case units were not in a crash. when unpacking the drones just bumped the antenna arms just right and antennas snapped. however I have issue that came up them when heavy usage has taken placed at max out speeds. also I can see this happening at certain high wind speeds creating a load on the antenna where the led lens fails.