Due to frequent issues with standard mail delivery, we will now only ship via Nekopos. These are grub screws used for adjusting string height on tremolo systems, 6-saddle Telecaster bridges, and similar applications. This set includes 4 screws at 6mm and 8 screws at 8mm, for a total of 12 screws. They are effective for replacing rusty screws like those in the fourth image, or when the head of a standard 10mm grub screw protrudes too much and gets in the way during palm muting. Precision-made in Japan, made of rust-resistant stainless steel, and in metric size. Being metric, they are compatible with most Asian-made guitars, including those made in Japan. Compatibility has been confirmed with GOTOH bridges and the "FENDER Standard Strat Big Block Chrome Tremolo Bridge Assembly (P/N 007-1014-049) MADE IN TAIWAN". They are NOT compatible with USA-made guitars and parts such as Fender USA/MEX, HIP SHOT, and Raw Vintage, as these use inch sizes. Although they are new, they are small parts. Before shipping, we visually inspect the screw threads, and if there are any concerns, we will test them by installing them on a saddle to ensure they tighten properly before packaging. *Please note (as shown in the third image): With pressed saddles, the 6mm screws may be too short depending on the string height setting for the 1st and 6th strings. We have confirmed that we have stock, so you can purchase immediately. Combined shipping with other guitar-related items is possible.