Specialized CPRO2 Trigger With Gauge Keeping You Inflated We all know that flats happen. There are ways to help prevent flats, but you should always carry a pump or CO2 with you. The Specialized CPRO2 Trigger With Gauge confirms proper inflation, making it easy to adjust pressure mid-ride. It features a thumb trigger that gives precise control and works with 16g and 25g cartridges. Features Easy to use gauge confirms proper inflation Thumb trigger gives precise control Works with 16g and 25g cartridges | Specialized | Cpro2 Trigger With Gauge Co2 Head With 16G Cartridge