Many First-Stage Regulators require a Spanner Wrench to Remove and Replace the End-Cap Assembly. The Highland by XS Scuba Spanner Wrench can work with Multiple Model Regulators with it Adjustable Range of 0.75" to 2.0". Wrench comes with Three Spanner Pins included: 0.185", 0.152" and 0.122". Fits most manufacturers' First Stages and is a must for the Serious Diver. Spanner Pins are threaded for Secure Fit and the Wrench has a Coated Steel Handle for Comfortable use. Wrench is covered by a 24 month limited warranty.