3/4 in. female threaded inlet No special key needed for adjustments, only a flat-head screwdriver Covers areas from a 20 ft. up to a 40 ft. radius in a part to full-circle spray pattern For use on medium to large lawn areas Gear-drive rotor helps ensure even and complete water coverage 4 in. pop-up sprinkler head Pack of 2 For outdoor use only For irrigation applications only Cold water use only Great for use over medium to large lawns O Can provide water coverage from a 20 ft. to 40 ft. radius Features a partial-to-full circle-spray pattern I have 12 (2packs) if you buy all you get a deal They are retailed at $20 a pair. So I will give a pair for $10. And if you buy all 12 pairs for $7 each so that would be $84.