Features and Benefits: Easy arc adjustment from 0? to 360? for 10-, 12-, 15-, and 18-VAN; 0? to 330? for 4-, 6- and 8-VAN. The textured base and collar are easy to grip, even when wet. A physical left edge indicator makes it easier to feel the fixed left edge. No special tools required. A small twist of the center collar increases or decreases arc setting. Stainless steel adjustment screw to adjust flow and radius. "Captured" screw slot prevents screwdriver slippage during adjustment. Ideal for watering odd-shaped areas. Blue filter screen (.02" x .02") (shipped with nozzles) maintains precise radius adjustment and prevents clogging.