Chamois grip or Shammy is popularly used by field hockey players to enhance the grip on their hockey stick. Chamois grips are "overgrips" which means they do not have adhesives on them, instead they are merely wrapped around the hockey stick handle.
They are very good at preventing the hands from slipping off the stick and are especially useful when wet, this is because they are designed to absorb moisture. Most internationals will use chamois grips over their existing grips for extra feel and grip in the wet.
The chamois grip for field hockey gets its name from the chamois leather but is not related to it now. Most of the grips available are now produced in Pakistan and India, not in the original town in France.
References
Chamois grip Wikipedia(Text) CC BY-SA