Bovie AcuDop II 770R Display Rechargeable Doppler Configuration:Doppler with 3 MHz OB Waterproof Probe Features a 55 75mm Interpupillary Distance Disposable Or Reusable disposable Features a 55 75mm Interpupillary Distance Adjustment 0 m 20 Pairs #PSTCUS15026 Small (15 mm x 20 mm) 1 MPN Configuration #AD 770R A2 AcuDop II 770R Rechargeable Display Doppler with 2 MHZ OB Probe #AD 770R A2W AcuDop II 770R Rechargeable Display Doppler with 2 MHZ Waterproof OB Probe #AD 770R A3 AcuDop II 770R Rechargeable Display Doppler with 3 MHZ OB Probe #AD 770R A3W AcuDop II 770R Rechargeable Display Doppler with 3 MHZ Waterproof OB Probe #AD 770R A5 AcuDop II 770R Rechargeable Display Doppler with 5 MHZ Vascular Probe #AD 770R A8 AcuDop II 770R Rechargeable Display Doppler with 8 MHZ Vascular Probe Literature The AcuDop II Doppler series is highly advanced for detecting fetal heart rates