Bicycle Head Stem Mount with 4 Prong Adaptor (sku 16731) Bicycle Head Stem Mount with 1" Ball for 1 1/8" Star Washer bike stems. Supplied with a 4 prong / lugg adaptor designed for 4 lugg cradles like Herbert Richter & BuyBits Strong secure mounting base. Machined from solid billet aluminum. Mount is British made. Fits 1 1/8" Star Washer Stems only - not suitable for Quill Stems. Fitting - Tighten to manufactures torque setting What's included? 1 x 1 1/8" head stem mount 1 x 4 prong adaptor. Available as mount base with 2 prong, 3 prong or 4 prong adaptors or as complete mounting options for mobile smartphones and GPS satnav systems - see separate listings.