4Pcs/set Skateboard Wheels Cover Assisted Dolphin Jumping Trainer Skateboard Accessories Universal fit for most skateboard wheels, and made from high quality super durable materials.These accessories stop your wheels from rolling, so you can experiment with tricks or work on balance.Anywhere Begin practicing tricks in your driveway, garage... even inside your house Skater Trainers work on nearly any skateboard wheels, 49 to 70mm in diameter.For kids of all ages The perfect gift for beginners who want to master tricks faster, or older skaters looking to re-learn old moves. Colour: Black Material: Silicane Package Contents: 4 x Skateboard Wheel Lock Only the above package content, other products are not included. Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.