Tacktick Speed & Depth System. Package Contains: T111 Micronet Dual Digital Display (Multifunction), T121 Micronet Hull Transmitter, T910 Triducer (Speed, Depth, Temp) , T111 Micronet Dual Digital Display (Multifunction), The Dual Digital Display shows two lines of data simultaneously. It can be configured at any time to display any information provided by your transmitters. T121 Micronet Hull Transmitter, The Speed, Depth and Compass Transducers link to the Hull Transmitter which sends the information to the Micronet Displays by wireless link. It can be sited anywhere convenient on the boat usually close to the transducers. .