58517-1 is an SDE die set designed for use with the PRO-CRIMPER hand tool system for crimping CST-100 open barrel contacts. This die set is compatible with wire sizes ranging from 26-22 AWG, providing reliable terminations for open barrel connector applications. The die set works with the PRO-CRIMPER II hand tool frame (354940-1) and can also be used with pneumatic power assist tools for higher volume applications. It is commonly used in networking, residential cabling, security, and telecommunications installations where consistent, high-quality crimps are essential.