Ego 3660582001 Compression Spring Compatible with Ego ST1500, ST1500-S, ST1500F, ST1500SF, ST1500XY, ST1510S, ST1510T, ST1520, ST1520S, ST1530 and STA1500 15" 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 head which uses a different spring. If your trimmer head has green lines that must line up to put line into the head, then your trimmer head 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 original appearance, ensuring your long-term use 
 You will get 4 Pack Ego 3660582001 Spring,Pls contact us first when you get some problem, we will offer you assistance asap