An indicator mechanism or gauge is located in a golf club and provides an indication that the "sweet spot" on a golf club head has been hit and the speed of the club head. The indicator mechanism includes a sensor mounted on the head of a golf club and an indicator positioned on top of the shaft of the club. The sensor detects the impact of the golf ball and hydraulically transmits this information to the indicator mechanism. A visual indicator protrudes from the top of the golf club shaft and provides an indication of the speed of the golf club.