5 year warranty and 100% water tested visible arrows indicate + or - arc adjustment Radius adjustment screw decreases radius up to 25% "Punch-thru" cover to protect nozzle retaining screw Easy-grip threaded cover 14 field-changeable nozzles Safety clutch for vandal protection Part circle models adjust from 40 - 360°; no tools required Expanded "arc dwell" on part circle models provides full coverage along borders Pressure activated wiper seal and strong stainless steel spring on pop-up models to ensure positive retraction High-tech micro filter protects reversing mechanism Streamlined large flow tube to minimize pressure loss through sprinkler Impeller flow regulator automatically matches rotation to nozzle selection Smooth impeller gear drive for highly uniform watering Large area, basket type, removable strainer for debris protection Standard Ready CheckTM check valve on T3 and T35 models is easily reversed in the field to a "check" position. Check valve holds back 12' (3,7 m/hd) of elevated water.