The Challenge Mini Pump is a lightweight bicycle hand pump with a reversible adaptor that fits the two most popular valves. A thumb lock ensures the pump locks securely on to the valve before inflation. Light. Easy to carry and use. It fits the two most popular valves. Hand pump. Compatible with presta and schrader valves. Maximum inflation pressure: 30 psi. Size H20, W7.6, D3.7cm. Manufacturer’s 1 year guarantee.