10-piece Steel Adapters Steel provides maximum strength and longevity. Each has O-ring to keep good seal. Easy recognition. Straight steel adapters are marked with number from 1 to 10. 90° elbow coupling adapter for limited access applications. 0-140 PSI PressureTestDiagnostic Tools High Precision Pressure Gauge Protective heavy-duty rubber cover around the gauge, dual scale (psi and bar) with readings of 0~140 psi and 0~10 bar 9PCS O Rings 9 spare o-rings of different sizes for replacement, with them, tools can be used with long-lasting seals to prevent leaks even under extreme conditions. Hose Brass connector for faster and easier installation,and high hardness, rustless, durable and good air sealing. The hose is made of nylon resin material, which is oil resistant and high temperature resistant.