Premium prong fasteners fasten papers and documents easily and securely with 2-3/4" Center to Center. Compressor (sold separately) fits tightly over base to hold up to 2" stacks of paper. Prong fasteners fit in regular two-hole punched paper. Bases are made of brightly finished, heavier-gauge, corrosion-resistant steel. Premium-grade steel delivers outstanding strength and durability. Compressors must be ordered separately for a complete fastener.