2 button handset comes in 2 types of connectors, 'STANDARD' or 'OKIN' type. Compare with pictures if your part needed has a 5 pin connector end with a 'V' shaped groove or a complete circle with no bottom groove:
-NO 'V' shaped bottom groove: ORDER 'STANDARD TYPE'
-WITH 'V' shaped bottom groove: ORDER 'OKIN TYPE'
*The handset does not have to look exactly the same as long as it has the 2 button function with the same connector end, in this case being a 5 pin (with or without groove).*