Specification Size: 1� (25mm) Inlet: Threaded (Male BSP) Material of Construction: Gun Metal Finish: Buff Polished Guarantee: For the period of 12 Months from the date of Supply. Item Description : 1� NB Inlet Air Release Valve, having floating Ball to pass air for dry risers. Material of Construction: Gunmetal Inlet : 1� threaded BSP Male