This is the Garmin Descent T1 Tank Pod Transmitter for Diving Computer Features: WATER-RATED: Descent T1 is built to withstand the elements and water-rated to 11 ATM. KNOW YOUR TANK: Get tank pressure, air time remaining, air consumption rate and battery remaining sent directly to paired compatible Descent dive computer. MULTIPLE DIVERS: Pair up to 5 transmitters to each compatible dive computer within a range of up to 10 meters. Track your every breath when you pair the Descent™ T1 transmitter with a Descent dive computer. Monitor up to 5 tanks via SubWave™ sonar technology so you can dive with multiple tanks or see your buddy's air levels. Descent T1 enables you to monitor tank pressure, remaining air time and air consumption rate for multiple types of diving.