"Raymarine P7 Plastic Through Hull Transducer Brand New Includes Two Year Warranty, The Raymarine E26009 is a plastic through hull transducer which is compatible with the ST40 instruments
It is compatible with aluminum and fiberglass hull material. P7 plastic low profile through depth tranducer operates on frequency of 200 kHZ and also includes 30 feet cable. E26009 Features: Through Hull Transducer, Part Number: E26009, Frequencey 200 kHz, Suitable w/ Aluminum & Fiberglass, Depth Transducer, 2"" Hole Diameter, Includes 30 Ft Cable, For Raymarine Models: ST40 Instruments"