TROWEL BLADE BLUE XL 8" x 16" COMBO BLUE STEEL PO Allen Engineering offers a complete line of finish blades, combination blades, and clip-on float shoes for your walk-behind or ride-on power trowels. We use high-quality steel or composite plastic with six high-strength rivets to maximize blade life. Forthe flattest floors, trust only Allen Finishing Blades. And, Allen Blades fit most other brands of walkers and riders.