Half the weight of traditional 3.5 V handles. Fits all Welch Allyn 3.5 V Instrument Heads. 120 minutes of on-time (compared to 60 minutes for standard NiCad handles). Made of sturdy CYCOLOY engineering resin. Low-battery indicator. Lithium ion battery technology that has no “memory” effect. AC charging module is easily removable from the handle and has retractable AC prongs (model 71900 only). Optional charging well adapter allows the handle to be charged in consoles or 71110 Desk Charger.