XI-9-1521 Dual Spectrum Ice Transducer Ice Transducer, Dual Spectrum CHIRP, 15/21 Degree, 130-250 kHz. No temperature Compatible with: All HELIX CHIRP units utilizing Ice Fishing mode, except HELIX 12 CHIRP…Continue readingHumminbird XI-9-1521 Dual Spectrum Ice Transducer [710273-1]