1. Compatible models: for STIHL PolyCut 2-2, PoluCut 3-2, FSA 45 FSA 57 FSE 52 trimmers. 2. To keep these blades in good condition and work better, make sure to soak them in water before using them. 3. Replacement blades for lawn mower.Good working conditions and easy installation.Durable and practical, easy to use. Specification: Material: Nylon. Total length: 90mm, aperture 12*7mm Package Content: 100pcs Plastic Blades Note: 1. The real color of the item may be slightly different from the pictures shown on website caused by many factors such as brightness of your monitor and light brightness. 2. The measurement allowed error is +/- 1-3 cm. Hand measured, sizes shown may vary slightly.