This 12.5x2.25-12.5x2.75 (including 12.5x2.25, 12.5x2.5, 12.5x2.75) inner tube (innertube) most commonly (though not exclusively) applies to 12.5x2.25 and 12.5x2.5 inch dirt bike and pit bike tires. Also with some 12.5x2.75 inch tires. Commonly used for 49-125cc mini bikes, dirt bike, pit bikes etc. The valve stem is straight.