The ERT is the only hi-tech micro processor system in the world for precise measurement of tension and playing characteristics on any tennis racquet. To use you simply connect the ERT 300 onto the centre of your strings, press a button and the screen will provide you with the accurate tension in kgs. An easy reference card included will show you what your tension is in lbs.

The ERT can be used as often as you like as a valuable tool to allow you to accurately see when your racquet requires restringing. When a racquet is strung too loose you will not have as much control over the ball. The strings will act as a spring and as a result you will gain more power yet sacrifice consistency. If the racquet is strung too tight you'll have more control but you will be sacrificing power.