Shure P4M Four Channel Personal Monitor Mixer When coupled with personal monitors, the P4M allows performers the ability to adjust personal mix levels onstage - even during a performance - without affecting the front-of-house system. The P4M can also be used as a small "piggyback" mixer in applications such as houses of worship, or courtrooms.PG Wireless handheld transmitter The P4M has a pair of 1/4-inch auxiliary inputs that can be used to add channels from other sources PG Wireless handheld transmitter The P4M has a pair of 1/4-inch auxiliary inputs that can be used to add channels from other sources When coupled with personal monitors, the P4M allows performers the ability to adjust personal mix levels onstage Can also be used as a small "piggyback" mixer in applications such as houses of worship, or courtrooms