Very useful. Works great.
At first, it didn't work. After read the operational instructions carefully, and follow it, it works great:
-- If the tops pin dial is turned up, you still need to have a little bit of back spin. If the back spin is turned off, this will cause jamming or multiple balls.
-- If the back spin dial is turned up, you still need to have a little bit of top spin
Verified purchase: YesCondition: Pre-owned