[Spare Parts for Practical Trimmers]: Contains 2 pieces of replacement spools for trimmers, 9m long, 1.6mm diameter, a spool cap and a spring. The coil can be inserted and removed without tools and does not damage the device. It is an indispensable replacement for every lawn mower [Robust Nylon Material]: ABS bobbin and durable polyamide nylon thread, good flexibility and long life. The cutting line of the mower with a diameter of 1.6 mm can reduce resistance and achieve a quick cut. [Automatic Feeding System]: The trimmer replacement spool for the automatic feeding system facilitates the tedious work of manual winding reels. To a certain extent, it reduces the workload, which is useful for improving work efficiency and facilitating mowing. [Easy to Replace]: Pass the mower line through the through hole and push down on the mower line spools. Install the reel cap mounted spring into the bottom slot of the mower, press and turn until the latch locks to complete the installation. [Compatibility]: Coils of cutting nylon thread Applicable to various models of lawn mower: GH400, GH500, GH600, GH610, GH900, GH912, ST6600, ST7000, ST7200, ST7700, ST7701, ST8600, ST9000, CST1000, CST1100, CST1200, CST2000, MT20 NST1018, NST1024, NST1118, NST1810, NST2018, NST2118, LST120, LST136, LST140, LST201, LST220, LST300, LST400, LST522, LST1018, LST55, L523, L5, L523, L523 and L5 BEST620.