Wood necks are not sufficiently strong to withstand the constant tension of steel guitar strings. To counter this string tension, steel reinforcement devices have been developed. This device not only strengthens the wooden neck but is also adjustable. Because of their engineered shape or design, these devices are called truss rods. As with many devices, there is ongoing refinement and new methods being researched. However, for the conservative minded or traditional player, there are two primary truss rod designs in common usage. Both of these designs are available from Warmoth. The first and oldest design we call "vintage". This consists of a single rod inset into a concave trench below the fingerboard. It is anchored to the neck at both ends. This is the rod used by both Fender and Gibson. The second design is a double rod, either made of two pieces welded together or a folded single piece. This rod is laid in a straight trench below the fingerboard and it is not anchored to the neck. This design has been used by Rickenbacker for many years. A third design now enjoying some popularity is a variation of the vintage single rod which is adjustable in two directions. While this design is touted to be superior, it is our opinion that well designed necks built from carefully selected and cured woods exhibit none of the problems this design is proported to solve. Which design is right for you? This is a personal choice with no wrong answer. To precisely replicate vintage tone, only the vintage rod will do. For stability and better sustain, only the double rod delivers. Which are the most important features to you?