... 4PR, 6PR 4. Inner Tube: natural rubber with straight valve5. Rim: iron rim with ball bearing or needle bearing6. Inner hole: 16mm ... Fast delivery time4, Best service team5,we are manufature of rubber wheel--wheel expert6, our production line is with professional working ... Wheel Barrow Co.,LTD, specializing in manufacture wheelbarrow, rubber wheel, tire and tube etc. We have 10 years experience on this ...