The SM Series transmitters use a standard Lectroson_ ics 5-pin type input jack for use with electret lavaliere mics, dynamic mics, or line level signals. A water resistant control panel with LCD, membrane switches and multi-color LEDs make input gain adjustmentsand frequency and compatibility mode selection quick and accurate, without having to view the receiver. The battery compartment accepts AA lithium or recharge_ able batteries. The housing is machined from a solid aluminum block to provide an extremely lightweight and rugged package. A special non-corrosive nish resists salt water exposure and perspiration in extreme envi_ ronments.