It depends on the type of floor what wheels you should choose.
The Interval Braked wheels (blocked when carrying no weight but rolling freely when seated on it) are the safest. There is one disadvantage: these wheels could cause some damage to your floor. The Free Running wheels are more gentle on your floor.
Caster Types
- Free running: Hard floor casters (black ABS plastic, 50mm diameter)
- Free running: Carpet casters (silver colored ABS plastic with black rubber, 60mm diameter)
- Interval braked: Sit-Lock casters (Black/Grey Rubber, 50mm diameter)
- Interval braked: Rise-Lock casters (Black/Grey Rubber, 50mm diameter)
- Fixed: Sliders (Black Plastic, 50mm – 60mm diameter)