General description This Ego 3660582001 compression spring is designed for seamless compatibility with various Ego trimmer models, including ST1500, ST1500-S, ST1500F, ST1500SF, ST1500XY, ST1510S, ST1510T, ST1520, ST1520S, ST1530, and STA1500. It serves as a versatile replacement option, also fitting Ego AH series heads like AH1300, AH1520, AH1522, AH1530, and AH1531, making it an essential solution for maintaining your 15-inch string trimmers. Technical specifications Color: Black Material: Metal Package Contents: 4x trimmer spring replacement Measurement allowed error: +/- 1-3 cm Compatibility and accessories Compatible with Ego trimmer models: ST1500, ST1500-S, ST1500F, ST1500SF, ST1500XY, ST1510S, ST1510T, ST1520, ST1520S, ST1530, STA1500 Also fits Ego AH series heads: AH1300, AH1520, AH1522, AH1530, AH1531 Note: Older ST1500F or ST1500SF trimmers may feature an AH1500 head, requiring a 3660650001 spring Usage To ensure compatibility, check if your trimmer head displays green