Package Includes: HBF12P plastic cap breathing 2 PCS  Product Model: HBF12P Plastic Hydraulic Breather Cap  Product Size: 1.57*1.57*1.77inch ,3/4NPT thread  Function: HBF12P vent cap acts as a ventilator to provide free flow of clean air to the liquid storage tank  High Quality: Made of durable plastic to block dust and dirt particles as small as 40 microns  Widely Used: Suitable for hydraulic oil tank and hydraulic oil reservoir