The XM mounts / holders provide satellite radio users with sensible and convenient alternatives for placement of their satellite radio receiver in the car or vehicle. Arkon offers more satellite radio mounts for XM and Sirius than any other company. For XM radio users, the Arkon Sat-Mount holders could not be any better. All the Arkon satellite radio XM mounts feature the T-slot adapter that connects directly into the back of the XM radio receivers.