1.Compatible with: All for I& Series, includes but is not limited to the following models: i3, i3+, i4, i6, i6+, i7, i7+, i8, i8+, E5, E6, E7, j7, j7+, 7550, 3550, 3150, 5150, 6198, and 7150. Non-Slip: The wheel tires are designed to improve traction on slippery or uneven surfaces, ensuring that the robot can move around smoothly and no slipping. Premium Quality: Made of premium rubber, and elastic, smooth running, the wheel not skid on the floor, make cleaning more efficient. Easy to Assembly: Cut and remove worn rubber tire, place new tire. Easy to replace the front caster wheel, snap in place, no tools required It is recommended that replace the tire tread every 6 to 12 months to optimal performance and the front caster wheel is regularly cleaned. color: Black material: plastic Package Contents: 2 x Side Brushes 2 x Tires 1 x Front Wheel Caster 1 x Screwdriver 1 x Cleaning brush Only the above package content, other products are not included. Note: Light reflection 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.