Twice the on-time, half the weight and fits more comfortably in your hand. Suitable for charging via the 71144 universal desk charger only, half the weight of traditional 3.5V handles, fits all welch allyn 3.5V instrument heads, 120 minutes of on-time (compared with 60 minutes for standard NiCad handles), made of sturdy CYCOLOY engineering resin, low-battery indicator, lithium ion battery technology.