The special feeling: DESTO F3 DONIC DESTO F3 has the special playing qualities of the FORMULA DONIC series. It is somewhat faster than a traditional spin elastic rubber. This rubber is soft and dynamic, has excellent control, and the sound of speed glue. We recommend DONIC DESTO F3 rubbers to the following players: Players who used to play with spin elastic rubbers without speed glue will have no adjustment problems by switching to DONIC DESTO F3. Players who have used speed glue, will find that using DONIC DESTO F3 offers an alternative to speed glue.