Model#: 900273-002 The Aquacom ® ComBox is a compact, self-contained one diver air intercom. It allows clear two-wire communications using a powerful 20-watt amplifier and a powerful front panel speaker, "Silver Bullet". The ComBox is rugged and offers many features others dream about. The Push-to-Talk (PTT) control is an industrial grade switch designed to be pushed all day long. The front panel speaker is small but packs a lot of sound. In hi-noise environments or where privacy is a concern, the optional deluxe headset is available. In all, the ComBox is the finest one diver box on the market. Specification Comparison of Hardwire Surface Units Features MK2-DCI Combox MK7 Battery Life 20 hrs. continuous use 6 hours continuous use with Alkaline batteries. 12 hours continuous use. Frequency Reponse 600-12,000 hz 600 to 10,000 Hz. 600 to 10,000 Hz Output Power (watts) 20 20 2 Charging Time 14 hours with optional gel-cell batteries 14 hours with optional rechargeable batteries. Controls Volume: Tender, Diver 1 & 2, Speaker, Cross Talk, PTT, Speaker On/Off, Select diver 1,2 or both. Volume: Tender, Diver 1. Volume: Tender, Diver 1, Diver 2, Speakers Heavy duty front panel or optional headset with boom microphone. Heavy duty, "Silver Bullet" front panel (10 full watts). Headset with boom microphone Low Battery Indicator LED type battery meter. n/a Audio Tone Battery Type (2) 6 volt lantern batteries (heavy duty) or Optional RB-6 rechargeable batteries. (16) AA Alkaline batteries or 12-volt front panel option. . 8-AA Alkaline batt. or optional RB-11 Dimensions (W x H x D) 14" x 10.60"x 6.85" 12 ½ lbs. 9"x7.85"x 3.4"5 lbs. 4 ¼ x 6 ¾"x 2 ¾"1 lbs.