It couldn't be easier to install. You remove the string locking screw from the low E-saddle on the bridge and replace it with one of the 2 D-Tuna locking screws provided, the spring assembly, and the D-Tuna. And that's just about all there is to it.-- Edward Van Halen

The D-Tuna is made from the highest quality hardened steel. The patented design allows for precise fine-tuning adjustment, is simple to set up, easy to use, and really works!

Each D-Tuna Kit Contains:     • D-Tuna     • Allen wrench     • Spring     • 2 long replacement string locking screws Finally... an easy way to drop from E down to D and back, without unclamping -Eddie Van Halen EVH D-Tuna Features:     • Precise fine-tuning adjustment     • Easy to use     • Patented design     • 2Made from the highest quality hardened steel

Eddie Van Halen D Tuna