This page describes Datamarine products using the 408P housing. Datamarine parts can be obtained from DMI, Inc.
Datamarine used the 6-blade P-121 paddlewheel with pointed tips. The RSW-TH and 33-108 paddlewheels can be used as a substitute.
The SX-120 is a speed-only transducer with a 10' cable ending in a BNC female conector. A BNC extension cable was often used.
The SX-160 and STX-20 are discontinued but can be replaced with the SST-109 from DMI. These two transducers both used a 33' 3-wire cable.