The DS-1 flow-through valve cap is designed for high pressure truck tire service. Seals like a high pressure valve cap, yet offers the convenience of an inflate through extension. It also performs like a check valve- the seal becomes tighter in the event of a core failure.The DS-1 reduces pressure check time by 65% offering an efficient money and labor savings alternative to the common valve cap. The heat resistant grommets provide additional protection for the extended high temperature running. The DS-1 consists of a tough, all metal housing, precision fit brass components and durable self-sealing O-ring.