12Pcs Insert Blocks Electric Guitar Tremolo Bridge Saddle Pro String Lock Insert Blocks ForElectric Guitar Bridge SaddleFeature: There are 12 String Saddle Insert String Lock Blocks In. It is used to tighten the strings on the bridge. Apply to Tremolo Bridge.Great Replacement: With their precise structure, these cartridge blocks are great repair parts or a replacement for your guitar. Premium Quality: Made of high-quality durable cast iron material, careful polishing, ensures a long service time. Application: The Tremolo bridge saddle is suitable for most tremolo bridge saddles. Color: Black Material: Iron Size: 8.15x4x5MM Package Content: 12 * Solid Electric Guitar StringsOnly the above package content, other products are not included. Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement error is +/- 1-3cm.