Material: High quality ABS spool and nylon stable line, are very good for lawn mowing, optimized for optimal and precise trimmers Spool Specification: 30ft thread spools are factory wrapped for a excellent food that 0.065 inch diameter portable cord supports fast cutting and longer service life, compatible with original AF-100 and RF-100 spool models Fast and seamless cutting: the replacement spool for the automatic feeding system facilitates the tedious work on manual winding spools. It uses centrifugal power and aerodynamics to reduce air resistance and achieve fast, clean cuts. Easy to Use: Replacement Thread Spool Fits GL280, GL301, GL425, GLC2500, GLC2500, GLC2500L, GLC3000, GL4525, GLC1825N, GLC1425N, GLC1825N, GLC1823L, GLC1825L, GLC3630L , ST5530, ST4525, STC1820 , STC1815, STC1820PC / EPC, STC1840 / EPC, ST1823. Advantage Pack: The package contains 8 replacement trimmer spools, 1 replacement replacement cover and 1 replacement spring. The coil cover is replaced by the RC-100-P cap, the spring is replaced by the RC-100-P spring. Excellent value.