Designed by Jim Burns in 1960 and manufactured by Burns London, this is a specially designed, adjustable, geared truss rod that allowed ultra-fine neck adjustments. It was first installed on Burns guitars and later high-end Gretsch electric guitars, most notably the Chet Atkins Country Gentleman beginning in 1970. Baldwin (yes, the piano builder) owned both companies, so it was easy to use one design on two product lines. The adjustment is made at the guitar’s heel, rather than at the usual headstock position. This system utilizes a hefty cog and worm assembly that is coupled to the steel truss rod.