Larger barrel version pumps more air volume for MTB riders. Large integrated 1-1/8 - diameter easy-to-read analog gauge provides the perfect inflation every time. Dual-Action (DA) doubles volume with each stroke and inflates tires up to pressure fast. Integrated dust cap keeps pump head clean and thumb lock lever insures air-tight seal. 2020 Bicycling Magazine Editor Choice for the best high-volumn mini pump.