The Crate TX15 battery powered portable amplifier is included in the
Cetacean Research Technology SS03-TX15
whale watching hydrophone system (as shown above), and is sold separately.

When paired with the Cetacean Research™ model CR1 hydrophone,
the combination serves serves very well as a robust hydrophone for whale watching operations.

Also see pro audio accessories.

view manual for the Crate TX15 (PDF)