Creanoso Guitar Truss Rod Allen Wrench Adjustment Tool for Martin Acoustic Guitars<div style="text-align: left;"><strong>[Product Information]</strong><ul><li><span class="a-list-item"> To adjust the truss rod on Martin Guitars and most acoustic guitar </span></li><li><span class="a-list-item"> 5mm ball end guitar truss rod. Dimension: 2.95" x 4.92" </span></li><li><span class="a-list-item"> Bonus: Creanoso Guitar Pick </span></li><li><span class="a-list-item"> Counter-clockwise on the nut always gives you some relief. Clockwise removes relief. Do your adjustment a little at a time with the guitar tuned up to pitch. </span></li></ul></div><img src="http://ecx.images-amazon.com/images/I/31kCz0Dx5lL.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/21KEBZfhO%2BL.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/314B-fpr0pL.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/21Ahpz8B2kL.jpg" noproxy>