The WG9725190102 air filter is mainly applicable to Si notruk H owo models such as How o 336, 371, 420, and engines like Weichai WD615, WP12, WP10, made of materials including iron, aluminum, high-performance 100% wood pulp filter paper (F7 level, 320 or 340 folds), environmentally-friendly PU glue, rubber, etc., with over 99% filtration efficiency to remove oil, water, dust and other particles, and advantages like increased air intake, stiffness, service life, galvanized anti-rust spiral iron mesh, widened weather-resistant and corrosion-resistant sealing sleeve, and enhanced sealing performance from rubber material; when installing, follow the manufacturer's instructions, clean the air box, ensure proper seating and fastening, check regularly during use, and determine replacement cycle based on maintenance indicator's air pressure difference or host manufacturer's regulations, with equivalent models like ASAS HF5629, Baldwin RS5538, Donaldson R003668, Dongfeng 110907050A, and Fleetguard AF26569.