ICP sends you three "15x6.0" tubes, with a straight air fill tap, forget it! its impossible to fill that ****, the refill tap broke from the tube when trying to angle it to fill the tube. So i went to the local tire shop, they hooked me up with 13x6.0 tubes, perfect fit with a 90 degree angled tap, they have been successfully trying this smaller tube out before with other gliders with the same problem. So when assembling them use A LOT of grease, thankfully the tire shop let me work in their shop when doing it.