General description Bi-Hex, cutaway fuel line sockets in small sizes designed for use in tight areas, specifically for BMW N54, N63, and S63 engines. Technical specifications 2 x Bi-Hex cutaway sockets: 17mm x 1/2"D 14mm x 3/8"D Usage Ideal for use on BMW N54, N63, and S63 engines. Suitable for many other makes and models. Side opening allows for 180° rotation.