DURABLE & LONG LASTING: High-quality nylons allow these blades to power through the thickest of weeds and light brush with minimal wear WHEN TRIMMER LINE ISN'T ENOUGH: High performance serrated nylon blades are for times when regular trimmer line just won't cut it and something more powerful is needed to tackle heavy weeds and light brush DIRECT REPLACEMENT: Fits any Weed Warrior, Shakespeare, or Rino-Tuff branded product that uses nylon blades (includes Push-N-Load 3 Blade, Ugly Head Hybrid, Ballistic Hybrid, and Rino-Tuff Hybrid trimmer heads) QUICK & EASY TO INSTALL: No need to remove the head, as the blades change in seconds via a simple post and button system that gets you back to cutting with minimal downtime