A large removable rubber band on the opposite end hold the balls in the tube until you are ready to dispense them

including passing shots

Featured as a 12 pack

and lets you know when it's time to restring (usually five to ten pounds of tension loss)

If youre looking for increased spin potential

Trigger Point GRID X Foam Roller Color:Black A large removable rubber bandUse the Trigger Point GRID X Foam Roller to break through your toughest, tightest trouble spots for relief from intense aches and pains. Its twice as firm as the original GRID with a three dimensional surface that allows tissue to aerate while you roll. This roller promotes the flow of blood and oxygen, both nutrients needed to repair muscle. Take this compact and travel friendly system to the gym, field or class for relief wherever you are. Perfect