Terre Products, 591221078 universal trimmer head replacement, bump feed string trimmer head accepts .05-inch to .105-inch diameter line and fits most trimmer models. This weed eater attachment has a line tensioning system with a split spool to reduce head vibration. All Terre products are manufactured with durability, reliability, and peak performance in mind. Accepts a minimum line size of .05 Inch and a maximum line size of .105 Inch * STRING TRIMMER HEAD Replace the bump feed string trimmer head of your gas-powered or cordless weed trimmer. * COMPATIBLE with most weed wacker, weed eater brands and accepts trimmer line sizes .05 inch to .105 inch. * PERFORMANCE – Weed eater head is smooth and durable. The large bottom cover taps on ground to advance line and allows head to glide while trimming. Large durable eyelets enhance line life. * PARTS – Bushings 10mm X 1.0mm LH, 10mm X 1.2mm LH, 8mm X 1.25mm LH, 12mm X 1.5mm LH ; Studs 7mm X 10mm LH, 8mm X 10mm LH, 7mm X 10mm LH ; 1 Plastic washer * COMPATIBILITY – * COMPATIBLE with most straight shaft string trimmers and brushcutters Echo, Honda, Husqvarna, McColloch, Makita, Poulan, Ryobi, Stihl * ENGINEERED TO LAST – Our universal string trimmer head replacement part 591221078 weed eater attachment has a line tensioning system with split spool to reduce head vibration, provide longer life, and perform better.