This is the Suunto Tank Pod Wireless Tank Pressure Transmitter for EON Steel Features: Easy pairing Multiple tank pressure readings Robust digital communications technology Compatible with Suunto EON Steel Labeling field for organization when using for several tanks Up to 10 simultaneously assignable Suunto Tank PODs Transmission distance max. 1.8m it works with the Suunto D5 Scuba Diving Wrist Computer The Suunto Tank POD is a wireless tank pressure transmitter that allows you to view current tank pressure with just a glance at your wrist. The robust digital communications technology brings not only improved stability but also new features such as multiple tank pressure readings. The reworked pairing procedure is very intuitive; just pressurize the system, hold your Suunto EON Steel close to the Tank POD and after a few seconds a menu pops up on the screen showing the serial number, battery status and the tank pressure.