Wireless temperature sensor/transmitter by LaCrosse Technology.

Product Specifications:

• LCD display of temperature (indoor/outdoor)
• Wall mount bracket included
• Weather resistant case
• Transmits to receiver
• Dimensions: 3.25" x 1" x 2.5"
• Operates on 2 "AAA" batteries
• Compatible with all LaCrosse weather centers models except for the "Proffessional Weather Center" series: WS2010, WS2210, WS2310, WS2315, and WS2510.