These carbon fiber extensions attach to the HRP Pro Mounts. They require the mounts for installation and are useless without the mounts.
This is the "Long" version designed to suit AMX/Mugen with Zoo Racing bodies. It includes 1 pair of extensions which will work for 1 body.
On consultation with RC Maker, we've determined that these extensions also suit the ARC A10 and Xray X4 when using Blitz CLA and TCN-S bodies.