Rod Wrench Nut Driver Instrument Accessory Tool 6.35mm for Guitar Neck Silver Tone 2 Pack

What is this? The rod wrench is the instrument accessory repair tool to adjust the neck of the guitar. Are there any advantages of the product? It is made of durable iron. End of the tool with a 5mm diameter screwdriver. Easy to operate. How to use it? Steps of installation:1.Loose the guitar strings; 2. Find the adjustment point(usually on the guitar head) and adjust; 3. Adjust with the screwdriver. What should I notice? The size data of the wrench is 30mm long it is the long one. If you need a short one (19mm) actually please do not purchase this one. Or it will cause the length to resist the wood and cannot be inserted into the holes.