PATIKIL Classical Guitar String Tuning Pin Gear 3.6mm Flat Hole Gold Tone for Guitar Tuning Pack of 6

What is this? This is a hex open hole gear, mainly used to replace old and dirty tuning pegs, and adjust guitar strings so that they don't come loose easily. What will I get? The guitar tuning peg button is in size of: Overall Height: 5.6mm / 0.22 inch; Outer Diameter: 10.2mm / 0.40 inch; Inner Hexagon Width: 3.6mm / 0.14 inch; The Gear rate: 1:18. In the package of 6Pcs × Guitar String Tuning Peg Gears Are there any advantages of the product? Made of iron material, it is sturdy and durable to ensure long-term use. The gear can effectively prevent the lead screw from slipping, so that the guitar strings are not easy to loosen. What should I notice? Please check the size of the installation part before purchasing!