1. Compatible with Einhell replacement thread spool, compatible with Einhell GCET 4530 set, compatible with Einhell grass trimmer models: RTV 400, RTV 550, RTV 550/1. And suitable for Gardenline Aldi: GLR 450 451 452 453 454 455 456 457 458 459, GLR 450/1 450/2 450/3 450/4 450/5, GLT 453 454 455. King Craft: KCR 450, KCR 451, KCR 500, KCR 500 GB. Craft: TCR 50, TCR 451, 50 TCR 451, TCR 500. Performance Power: PWR400DGTA, PWR550GT. 2. Trimmer spools adopt quality ABS spools and durable polyamide nylon rope for flexibility, not easy to break, and support fast cutting. 3. The unique shape of the grass trimmer thread reduces resistance, allowing for more efficient trimming and a larger trimming area. Plus, the pliable, flexible design can stretch and cushion in the event of an impact, resulting in a longer service life. 4. You will receive 6 lawn trimmer spools, 2 x TLE021 spool covers, wire length: 10 m, wire diameter: 1.6 mm, to meet your mowing requirements.