Zinc Stay Roller Without Screws, Designed For Use As A Guide On Large, Sliding Doors Up To 2-1/4" Thick, Embossed Frame With 2 Wings Provides Greater Bracing & Holding Strength Versus Conventional Singe Support, Corner Iron Frame, Delrin Wheel Ensures Rust Free Operation & Is Formed To Prevent Dirt From Clogging Or Accumulating, Wheel Is Reversible, It Can Be Used On Either Side Of Frame, Convex Roller Wheel Prevents Gouging Of Door, Roller Is Adjustable, Display Pac Loose.