Velowurks Prime Floor Pump, Black/Silver/Chrome Aluminum and steel construction, all pressure facing components are threaded together for a secure fit Oversized plunger shaft is polished with a tough anodized finish and runs through a bushing for smooth operation and longevity Extra large, easy to read gauge with a responsive movement for accurate pressure reading Tall air chamber pushes more volume without straining your back Cast dual head is compatible with both Schrader and Presta valves