Usage Tips:Ego 3660582001 Compression Spring Compatible with for Ego ST1500, ST1500-S, ST1500F, ST1500SF, ST1500XY, ST1510S, ST1510T, ST1520, ST1520S, ST1530 and STA1500 15inch String Trimmers Ego 3660582001 Replacement Compression Spring Compatible with Ego AH1300, AH1520, AH1522, AH1530 & AH1531 Trimmer Heads IMPORTANT NOTE: Older versions of ST1500F or ST1500SF Trimmers may have the AH1500 trimmer which uses a different spring. If your trimmer has green lines that must line up to put line into the , then your trimmer is model AH1500 and you need part Number 3660650001 Ego ST1500 replacement spring has good elasticity, even if it works for a long time, it can restore its appearance, ensuring your long-term use Please note: the physical slightly color difference or difference, does not affect the use, please do not mind, thank you! Colour:Photo Color Material:iron Package Contents: 5 x 3660582001 Trimmer Compression Spring Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.