Graph Tech Supercharger Kit NV for 4mm Posts Nickel Kit includes: ResoMax NV2 4mm Bridge with String Savers, TUSQ XL Slotted Gibson Style Nut & 240 Grit and 600 Grit sandpaper Bridge Specs: 4MM Post - Post Spacing: 2 29/32" - String Spacing: 2 1/16" - Radius: 12" - Thread: M5 x 0.8 4h TUSQ XL Gibson Style Slotted Nut Specs: Length: 1 3/4" - Width: 3/16" - Height: 3/8" - E to E Spacing: 1 7/16" This SuperCharger kit will fit most Gibson USA guitar as well as many others. Available At Ant Hill Music!