Just small enough to carry or clip on to the bike and just big enough to pump efficiently the PMP-4 dual head mini pump is built like all our tools - solid! All aluminum barrel construction ensures long life and smooth operation. Soft touch grips and a flip-out handle make it easy on the hands. The PMP-4 is Presta and Schrader valve compatible and includes mounting hardware to securely attach to water bottle bosses. (Max. pressure: 90 psi / 6 bars)