The Keith Banjo tuners are the best D-tuners you can get for your guitar. They are made from stainless steel and carry a life time guarantee. You use them as normal tuners and D-tuners with adjustable stops. Excellent return to pitch stability,and your guitar will fit into its case perfectly. They work great if your into alternate tuning, and we use them with our stringbenders to get great steel-guitar effects.(Check out the demo in the video-"Double Bender Workout"). If you have vintage style tuners the peg holes will need to be enlarged. When ordering tell us what string you want them for so we can match the correct post-size. For the vintage tuners you can send us your guitar neck for a custom fit. Cost: $100.00 per peg. Write or call for installation charge.