Welcome to quality with a pair of Air-Loc 4.00-18, 4.00-19 combination farm tire inner tubes for implement tractor tires that require a TR15 short, wide base rubber valve stem. These butyl rubber inner tubes are designed to fit Ford 8N and Ford 9N front tractor tires along with any other applications that call for a 4.00-18 or 4.00-19 inner tubes.