... Pneumatic wheel3. Tire Ply rating: 2PR, 4PR, 6PR 4. Inner Tube: natural rubber with straight valve5. Rim: iron rim with ball bearing ... or needle bearing6. Inner hole: 16mm, 20mm , 25mm7. Packing: in ... delivery time4, Best service team5,we are manufature of rubber wheel--wheel expert6, our production line is with professional working ...