Of the highest performance and price ratio, gl300 is up to a range of 18 meters. Strong against noise High depth accuracy Easy to use Lower price Excellent service Gl-system-300 receiver System freq :30khz Batteries :6 c-cell off shelf batteries/rechargeable battery Batteries life :18/10 hours continuous operation. Display :industrial rated lcd graphic display Telemetry :5 channels of license free radio. Range up to 600m Dimensions :30cmx13cmx67cm Water proof :ip65 Gl-system-300 display Power :6 c-cell off shelf batteries or 12-32 vdc of a hdd Batteries life :18 hours continuous operation with 6 c-cell batteries Display :industrial rated lcd graphic display Telemetry :5 channels of license free radio with range up to 600m Dimensions :14cmx13cmx13cm Water proof :ip65 Gl-system-300 transmitter Transmitting freq :30khz Batteries :2 c-cell off shelf batteries. Batteries life :12 hours continuous operation Range :up to 18 meters depth Roll :12 oÆclock segment Pitch :0.1% resolution Temperature :under 85 centigrades Weight :0.68kg Dimensions :standard Water proof :ip67 Packing in plastic case 85cm45cm22cm 6.2kg