Bicycle 1inch Ball Head Stem Mount with Short Double Socket Arm and 1inch Ball Diamond Base (sku 30644)Bicycle 1inch Ball Head Stem Mount with Short Double Socket Arm and 1inch Ball Diamond Base. This mount is designed with a 1inch diameter ball and socket system that has adjustment points at both ends of the double socket arm allowing for almost infinite adjustment and perfect viewing angles. The head stem mount is British manufactured from solid billet aluminium and fits 1 1 8 inch Star Washer Stems only. Not suitable for Quill Stems. Fitting;