This 12V diaphragm pump has an open flow rate of 3.5 GPM and the ability to self-prime up to 6 feet. The rated pressure is set at 55 PSI (40-80 PSI adjustable), and the open water flow perfectly fits all settings. The price drops from $47.99 to $23.44 when applying the code "33B0BX69W9B5" at checkout. Shipping is free w/ Prime or on orders above $35.