... wheel(2) Color: Black ,red, yellow ,green ,gray(3) Bearing: Ball, roller, nylon or without bearing(4) Type: Solid, pneumatic, PU foam, semi-pneumatic ... , hollow etc.(5) Material of tire: Our rubber wheel has high natural rubber ... , 3.50-8, 4.00-4, 4.00-6, 4.00-8, 4.80/4.00-8, 5.00-6, 6.50-8 Rubber Wheel 14*4 solid