Ultrasonic sonar ranging module prowave srm400 this module is a sonar ranging device that will work with all b prowave b b pr b or b ep b type transducers the module includes the b pw 0268 b b 35 1825 b ultrasonic sonar ranging ic and a b 400ep14d b b 35 1760 b 40khz air ultrasonic enclosed pulse transit transceiver the feature set and performance of this device make it ideal for prototyping distance measuring systems such as vehicle reversing systems prowave srm400