608 Bearing Quad Skates with 5 balls Ceramic Si3n4 Specification：

Dimensions:  

Inner Diameter: 8mm

Outer Diameter: 22mm

Width:7mm

Material: Chrome steel(Gcr15) inner& outer rings + Si3n4 black ceramic 5 balls

Features:

1.With ceramic hybrid inside balls

2. With 5 balls design

3. Single side seal----Easy-clean

4. With high quality material ,durable ,faster and slient

Application:   

Inline roller skates, speed skating, skateboard, longboard, scooter wheels...

608 Hybrid Ceramic Bearing Skateboard With Si3n4 5 Balls Pictures: