Auto Winder II Replacement Trimmer Head, Eliminates Tangled Spools With Easy Feed Technology, For Easy Line Changes, Simply Insert The Line & Crank The Bump Knob, You Get The Continuous Cutting Benefit Of A Bump Head Without Having To Open The Head To Change Line, Designed To Accommodate Trimmer Line Sizes Between 0.080" - 0.105" Diameter, Works On Gas Trimmers Only. This product can be used easily. This product is manufactured in China.