6.0V, 5000mAh, Sealed Lead Acid Battery fits Welch-allyn, 300, 300 Vital Signs Monitor, 30WhBattery Fits Models: 300, 300 Vital Signs Monitor, 420, 420 Vital Signs Monitor, 4200 84, 42mob Spot Vital Signs Monitor, 42nob, 450eo, 450to, 45meo, 45mto, 45neo, 45nto, 501 0015 01, 5300, 5300 101, 53nop, 53ntb, 53ntl, 53nto, 53nto Vital Signs Monitor, 53oto, 53oto Vital Signs Monitor, 63ntb, Spot Check 420, Spot Check 4200b, Spot Check 420tb, Spot Check 42m0b, Spot Check 42mtb, Spot Check 42n0b, Spot Check 42ntb, Spot Vital Signs Monitor, Vsm 300,