MTD Genuine Factory Parts Replacement Small Bump Knob for MTD Non-Brushcutter Trimmer Heads 791-15066B - The Home Depot
MTD, TROYBILT Quick load String Trimmer Head 796-00072 NEW 841 | eBay
Head Assembly - 841-032392S | Troy-Bilt US
Amazon.com: Oregon Gator SpeedLoad Universal 4-1/2” Trimmer Head & Line for Gas String Trimmers & Multi Tools Up To 25cc. Fits Ryobi, Homelite, TroyBilt, Stihl and more : Patio, Lawn & Garden