Hennessey strap locks.The industry standard strap lock, with its familiar spring-loaded pull knob design, keeps you from accidentally dropping your strap worn guitar. Now, the zinc die-cast Hennessey Euro-lok Series Strap Locks made this standard design even safer, easier and more ergonomic to use. Each pair comes with a threaded wing nut to install your locks on the guitar instead of the standard hex nut. Plus, an included wrench (which also doubles as a bottle opener) can be used to ensure it is tight. An extra strong screw won’t strip or release over time.