PAGOW 4mm & 5mm Guitar Truss Rod Wrench, Allen Wrench Tool Ball End for Martin Acoustic Guitar, Truss Rod Adjustment Deep or Narrow (Black)

Works great and the right size 👍

Ordered this for use on a Martin 000cjr-10e Streetmaster. The 5mm size is what I needed. The length of the wrench is perfect for that guitar.

My daughter was kindly given a lightly used Yamaha steel strung acoustic. Nice guitar but the truss rod needed tightening to reduce the bow in the neck and lower the action. It was very hard to adjust with a regular Allen wrench so ordered this set. This is the perfect tool for the job, and I soon had the guitar set up perfectly.

I wouldn't even think about adjusting a guitar truss rod without it.

I had to adjust the neck of my guitar due to the low E string buzzing. Bought this set because of the two different sizes. I inserted the first one I picked up, turned it a little then checked the string. Buzzing was gone. This set should be in your guitar tool stuff for sure.

These are good enough for most tech work or for travel where you might accidentally donate them to the next gig band. Plus they're inexpensive.The 4mm wrench wasn't bent at a proper right angle; which suggest that QC was lacking. Doesn't really affect the usage.In terms of fit, the 4mm measured 3.94mm, 3.96mm, and 3.98mm in cross dimensions.The 5mm measured 4.90, 4.91, and 4.90mm.They are really long on the ball side and reasonably long on the flat side. This is actually a really nice feature since you might prefer one length or the other in different situations.I'm happy with the purchase.

Im not a luthier by any means and mostly afraid to touch my guitars for fear of doing something wrong, but buying these truss rod wrenches was a great investment.All i can say is go slow on any adjustments and you will be fine. I have a 20 year old martin dreadnaught i thought was a goner but this has made it enjoyable to play again. My newer 2 year old martin needed a tweek as well and im not so fearful of twisting that rod anymore.1/4(25*) to 1/2(45*) turn at a time, let it sit for a day or two and test the action. If you are straightening the bow, remember to loosen the strings a half step or vice-versa.Also, invest in a humidifier. Both my guitars just love water. A constant 71* kind of mimics winter up north; the dryness. Ive adjusted my newer martin twice now as its stabilized and its really nice to be able to fine tune it without leaving it at a guitar shop for weeks let alone the price. Good luck and happy strumming.

If you have a Martin, you will use this product. I’m sure it will work for many other brands.