From a black box the magician removes a golf cube, which is for beginning golfers. The performer explains all you have to do is get the cube into the hole (the empty black box) . As he explains this he places the golf cube into the box. He further explains that beginning golfers need to practice until they can get a hole in one. He places the golf cube into the black box and when he turns the box upside down, instantly a REAL golf ball drops out! The ball is handed out for inspection. 
The magician says that after beginners master getting the cube into the hole, they get to move onto the advanced level. As you might guess, when moving to the advanced level beginners get to play golf on a green! Astonishingly, after the lid is removed a GREEN CUBE appears inside the black box and is dumped out and placed in the spectator's waiting hand. 
 
By the way, the green cube sports a black dot depicting a golf hole. 
 
The final surprise and BEST feature of this mind-blower is that EVERYTHING can be examined straight away! It's brilliant! 

The black box misures cm 6,5 x 6,5 (in. 2,5 x 2,5).