Compatible Modelscompatible GE-CT 18/28 Li and GE-CT 18/28 Li TC,4 pack Replacement Spools Specification and Packing List: The line on each replacement line spool is 5 meters long. The line is 1.6mm gauge or diameter. 4 x spare trimmer spool. Autofeed System Replacement Spoolthe spool can use centrifugal force to transport the trimming line as needed, which reduces the tedious work of manually winding the spool and improves efficiency. High Efficiency The spool line can be stretched and cushioned under the impact of a hard surface, and its aerodynamic shape allows for more effective cutting and less resistance, making weeding more efficient. Durable MaterialThe trimmer line is made of durable ABS spool and premium nylon line, durable and cuts lawn faster. Pliable and flexible allowing the line to stretch and cushion on impact with hard surfaces.