Officemate Prong Paper Fastener, Compressors. 3 1/2 inch Base, Box of 100 (99855) Fastens papers and documents easily and securely 2.75 inch Center to center Made from corrosion resistant steel Compressors fits tightly over base to hold paper For use with all 2-3/4" center-to-center prong fastener bases Corrosion resistant steel. 100/box