To achieve high quality HPLC separations, solvent fl ow rates must be accurate and reproducible. With software-controlled, independent piston design, the Agilent SD-1 Solvent Delivery Module meets these exacting requirements. To maximize fl ow reproducibility, a pressure transducer in each pump head provides instant flow, and pressure feedback to the drives. The dual motor, high resolution drives ensure supremely accurate solvent delivery and the pulse free pump design extends column life. An easy change of pump heads gives flow rates from 0.01 mL/min to 800 mL/min, up to 6,000 psi, showing that the SD-1 is ideal for use with analytical and preparative systems, providing seamless scale-up that is simple to achieve and economical in operation.