Butterfly Sriver Table tennis rubber and its variations have long been our best selling rubbers. The original Sriver has a medium hard sponge and offers great all-round performance. With the advent of speed gluing, FX was introduced with a softer sponge witch works well with the speed glue. Recently, many of our professional players expressed a desire for a Sriver product with the power of the original Sriver and the speed gluing properties of FX. Thus, Sriver EL was born. All three Sriver products have the same top sheet the difference is in the sponges. Super Sriver is a unique product. It has a different topsheet than the other Sriver products. This topsheet was designed to help the ball leave the table tennis racket quicker. This benefits the hitter and the counter driver the most.