This is the VoltWatch2 on-board Receiver Battery Monitor for 4.8V and 6V NiCd and NiMH receiver packs.

   
FEATURES:
7-LEDs provide instant, accurate battery voltage status of Low, Safe or Max. Only one LED glows at a time
Small switch to select 4.8V or 6V battery
Very lightweight, only .15oz (4.3g) unit can mount on the side Frame, or under the canopy
Draws amazingly low current - from 4-34mA depending on the battery voltage
Plugs into any open receiver channel using a Futaba J connector

INCLUDES:
One VoltWatch2 On-Board Receiver Battery Monitor w/Futaba J plug
One 1.5"x1" piece of double sided mounting tape