This comes from the TREKER web site where there is a lot of information on these "GREAT" Guitars and Basses. TREKER has something very special and believe me I am really impressed with this Bass! This is my first experience with the TREKER Neck and I am now a believer!! Trekerís patented Tension-Free Floating Neck works by transferring string tension to an internal cold rolled steel bar and away from the wood of the neck. On conventional necks a thin steel truss rod is used to compress the wood of the neck to counteract string tension. This compression creates dead spots and can contribute to neck warping under changing atomospheric conditions. Compression also dampens the natural resonant qualities of the wood - with much the same effect as placing your finger on a drum skin before striking it. Treker also builds replacement necks for 22 Fret - 25Ĺ scale guitars and 34" basses that feature this same advanced technology. All Sustanium necks feature a LIFETIME GUARANTEE!!!