SPG 16-12 is a model number of 16mm x 12mm stainless steel union straight reducer push-in air fittings, which can connect 6mm diameter and 12mm diameter tubing. Constructed of high grade 316 stainless steel, these durable union connector reducer push-in fittings provide a simple push-pull method of connecting pneumatic tubes and can hold a variety of tubing material including nylon, PU, PA, Teflon...