The Shakespeare Auto Winder II Bump Feed Trimmer Head eliminates tangled spools with its easy feed technology. For easy line changes, simply insert the line and crank the bump knob. You get the continuous cutting benefit of a bump head without having to open the head to change the line. Universal Autowinder II works with most gas curved-shaft and straight-shaft trimmers. Designed to accommodate trimmer line sizes between 0.080 to 0.105 inch in diameter. Ideal for trimming and edging grass.