Package Included: 12 x replacement trimmer line spool ( CMZST080 & CMZST0803 ) 1x replacement spool cap,1x spring. The trimmer replacement spool Suitable String Trimmer Models: Replacement spool for CMCST910 Series compatible with Craftsman string trimmers. String Trimmer Line: Premium about 20 Foot/ 6.1 m in length and 0.08-inch/ 2 mm in diameter.String Trimmer Spool Line easily cuts through grass and weeds. Llows less drag for more efficient cuts. Pliable and flexible allowing for the line to stretch and cushion on impact with hard surfaces. Auto Feed Grass Trimmer Spool Line: High-quality ABS spool & durable polyamide nylon thread, flexible and long service life. The trimmer replacement spool utilizes centrifugal force and aerodynamics to reduce drag ,Achieve fast cutting and utilizes centrifugal force to feed the trimmer line as it is needed. The auto feed system replacement spool eases the tedious work of hand-winding spools. Pre-wound,ready to go: Each replacement spool comes pre-wound and may be replaced easily in a few seconds.It is very easy to assemble and remove, you can snap it into the right place and then assemble them quickly and easily just by hands, no need other tools. Premium Service: Easy to use and install pre-wound spool saves you time and energy, If there is any questions of the quality, please contact us , we’ll offer a suitable solution within 24h. CMZST080 CMZST0803 8pcs String Trimmer Line(0.08",20Ft) with Cap Head,Weed Eater Wacker Replacement String Line,Compatible with Craftsman CMCST910 Series, CMCST910M1 CMCST910B