This is a versatile, scissor-action handheld pneumatic calibration pump designed to generate both vacuum and medium range air pressure. It features a robust anodized aluminum body with a built-in push-button or switch mechanism to easily toggle between pressure and vacuum generation. It is equipped with a fine-adjustment volume vernier wheel for precise pressure targeting, a needle release valve, and a flexible high-pressure micro-bore hose with standard adapters to connect reference master gauges and devices under test.