Ocean Reef Snorkie-Talkie Surface Unit is a long range walkie talkie with 500m / 1500ft range. Works to any direction any number of units. This unit is compatible with other brands, if using same frequency. Designed specifically for use with Ocean Reef Snorkie-Talkie snorkeling communication units. This handheld radio is ideal to communicate withyour child or other family member who is in the water wearing an OCEAN REEF full face snorkeling mask and a Snorkie Talkie. 4 channels Long range Easy to use Adjustable volume PTT timer off Keypad locking 3 AA alkaline batteries (included) This product is not waterproof.