Instrument Isolation Valves Buy A Gauge Sale! from 1300 /per Size 1/4" BSP 3/8" BSP 1/2" BSP Gender Female to female Male to male Material Brass Stainless Steel Qty. Add to Cart This item is currently on backorder but you can still purchase it now and we'll ship as soon as more become available. Heavy duty brass and stainless steel isolating ball valves - often called gauge cocks. Available in numerous connection sizes. Tweet