The String Retainer Block is an alternative to individual ferrules on string-through guitar bodies. Instead of drilling 6 individual holes for ferrules, a router is used to create a perfect recess that the block drops into. Never deal with misaligned ferrule holes again! The blocks are made of wenge and available for several bridge types (string spacing).
Please Note: the template is also available separately. The template requires a 1/2" guide bushing collar and 1/4" router bit (not included).
Router Guide Bushings 101: A guide bushing mounts to the router's sub-base with a tube that protrudes below. A straight router bit extends through the tube. The outer surface of the tube rides against an edge guide or template, keeping the bit a set distance (offset) from the edge guide or template. (Read the complete article "Understanding Guide Bushings" at Wood magazine)