They're equipped with special valves that let air in and keep water out. (geekwrapped.com)
Multi-chamber shocks with special valves make the Colorado's range - topping ZR2 at home jumping ramps, crawling over rocks, or cruising about town. (extremetech.com)
SVT modifications on the Mustang GT's 5.0 - liter block include GT - 40 style cylinder heads with special valves and roller rocker arms, a unique intake manifold, camshaft and exhaust among other things. (automobilemag.com)