Haoye 1 Pair Adjustable Engine Mounts 20-180 Class For RC Airplanes Parts Model Suitable For methanol Gas Engines. Package includes 1 pair. Size (Base Diameter x Height of mount): Giant: D65×H130mm (Suitable for class 120–180 fixed wing aircraft); Large: D60×H110mm (Suitable for class 60–120 fixed wing aircraft); Medium: D50×H80mm (Suitable for class 40–70 fixed wing aircraft); Small: D45×H73mm (Suitable for class 20–48 fixed wing aircraft). Designed to support RC airplane methanol gas engines. Constructed from nylon material. Compatible with class 21–120 fixed wing aircraft. Compatibility Disclaimer: This is an aftermarket replacement part. Any brand names or model designations mentioned are used solely for the purpose of demonstrating compatibility.