In 1910 the Army adopted two models of shelter half. The Cavalry pattern eventually became what we today know as the M1910 shelter half that was issued all the way through WWII. The Dismounted or Infantry patter (this one) was a smaller trapezoidal design. It was designed for use without issue tent poles, supported instead by a bayonet in the rear and a rifle in the front. After extensive use on Mexican Border Service, this design was abandoned and the larger Cavalry pattern became a standard for all branches.