Davis Standard Wireless Repeater w/Solar Power 
Wireless Repeater with Solar Power
For longer distances or to improve reception in troublesome areas, add one or more Wireless Repeaters. Transmitting and receiving range for each repeater is up to 1000' (300M) outdoors, line of sight; typical range through walls under most conditions is 200' to 400' (60 to 120M). Includes solar panel, regulator circuit, and rechargeable battery.
Use up to eight repeaters with a single wireless station, or form a network of weather stations by linking eight repeaters to eight different wireless stations.
Compatible with Vantage Pro2 and Vantage Vue only; not compatible with original Vantage Pro.
Quick Guide (pdf)
Owner's Manual (pdf)