Original two-piece, self-locking fasteners give you a secure, book-like binding to help you save on document storage space. Sturdy fasteners in specialty sizes are great for non-standard applications. Made from heavy-gauge, high-grade material for added durability. Complete—Prong base and compressor. Fastener Subtype: Two-Prong Set; Fastener Capacity [Nom]: 3.5"; Fastener Sheet Capacity: 350 Sheets; Center To Center: 4.25".