Haoye 1 Pair Model Aircraft Fixed Wing Split Isosceles Engine Mounts For 12-120 Class RC Airplanes Parts Model This engine mount is designed to support model aircraft engines and is suitable for class 12 to class 120 fixed wing RC airplanes.It comes in three size options: S: Base length 38mm, height 48mm, hole-to-hole distance 30mm, hole diameter 3.0mm, suitable for class 12-25 aircraft M: Base length 52mm, height 88mm, hole-to-hole distance 41mm, hole diameter 4.5mm, suitable for class 40-50 aircraft L: Base length 70mm, height 100mm, hole-to-hole distance 58mm, hole diameter 5.0mm, suitable for class 60-120 aircraft Made from nylon material that helps reduce engine vibration.Package includes 1 pair of engine mounts.