Material: Plastic, Length: 95 mm. Suitable for Ferrex aldi 20V / 40V battery trimmer, FAR 20-ia FAR 20na Note: To make these blades work best, be sure to soak them in warm water for 24 hours before use. Good for grass and thin brush, not for young trees or other hard materials. For best use, avoid using this attachment for edging, working with bricks, chains, or wooden fences. Quantity: 100 plastic blades for Ferrex aldi trimmer, perfect replacement for the original blades.