1.pass ISO 2.16*x4.00-8 air wheel:ball ,metal powder bearing 3.steel rim in 1.0mm, 4.load capacity:100kgs 5.powder coating We could produce all kinds of solid and rubber wheels for wheel barrow ,such as 6",8".10"12"13"16" any specification.rim:steel or plasticbearing:ball or roller bearing is availablematerial :rubber or plastic in tire 16"x4.00-8 air wheel