This is a manufacturer replacement product. Part numbers include: 511010601, PT104, PT-104 Thread Size: M10x1.25 Left Hand Compatible with Models including: Redmax BC250, BC225DL, BC2300, BC2300DL, BC2600, BC2600DL, BC2601DLS; BCX2600S; EX2-BC; EXZ2401S, EXZ2401SBC, EXZ2450SBC, EXZ2500SBC; TR2300S, TR2301S, TR2350S Weed Eater Compatible with: Redmax BCZ2400S, BCZ2400S, BCZ2401S, BCZ2401S, BCZ2450SVBCZ2460S, BCZ2460TS, BCZ2600S, BCZ2600SU, BCZ2600SW, BCZ2601S, BCZ2601SW, BCZ2610S, BCZ2610SU, BCZ2610SW, BCZ262DL, BCZ2650S, BCZ2660TS, BCZ3000S, BCZ3000SW, BCZ3001S, BCZ3001SW, BCZ3050S, BCZ3050SW, BCZ3050T, BCZ3060TS Weed Eater Description: This is a manufacturer's replacement product. Parts may differ in appearance but are functionally equivalent to the previous part. Trimmer Head Application: weed eater head Replaces of maintenance 511010601 PT-104 Trimmer Head for RedMax BC2600 BC2600DL BCX2600S BCZ2600S, BC, BCX, BCZ, EX, EXZ, TR, TRR Weed Eater