The barrel nut wrench works to tighten both the 556/308 Switch™ barrel nuts as well as the Night Rail™. The Night Rail™ comes with a tool, but the Switch™ rails do not. You can use the standard 3 prong DPMS tool for the 308 and a standard AR15 spanner wrench for the 556 Switch™ rail. Please follow proper Switch™ installation procedures.


  • 4130 steel hardened to 38-40 RC
  • 556 Spanner wrench
  • 308 DPMS barrel nut compatible
  • Both 1/2 & 3/8 square
  • Black oxide coated
  • Made in the USA!