The PROXP-20RC-THUNDER-W add-on subwoofer kit allows you to add an aftermarket subwoofer to your 2020+ Polaris RZR Pro XP model vehicle with direct factory integration to an existing 2-speaker OEM system. The kit features our PROXP-20-SW 10" loaded, high output subwoofer enclosure coupled with the MUD600-1 monoblock amplifier, amplifier mounting rack and all wiring needed for installation.