One of Hagstroms last projects before their Swedish production stopped was a collaboration between their chief guitar designer Per-ake Olsson and Rutger Gunnarsson, bassist for the Swedish super-group ABBA. This resulted in the Super Swede Bass, which was used by Rutger throughout ABBAs final North American tour in September/October 1979. Only 364 of these basses were produced before Hagstrom ceased guitar production in Sweden, and over the years they've become a sought-after collectors item. Hagstroms original Super Swede bass had a neck-through design, a feature found typically on more expensive hand-crafted bass guitars. Neck-through basses offer unrestricted access to the highest frets since there is no heel needed to support the neck/body joint, and also tend to have more sustain than traditional set-neck or bolt-on instruments. All Hagstrom electric guitars and basses include their patented H-Expander truss rod. Providing tension at both ends and running the entire length of the neck, the rigid yet light-weight alloy truss rod allows for a very low action and thin neck, two factors that were instrumental in earning Hagstrom its reputation as the worlds fastest playing guitar. The H-Expander truss rod not only provides ultimate neck stability, but it also contributes to Hagstroms unique tone. Longer sustain and a round attack are some of the sonic characteristics the H-Expander adds to the tonal essence of Hagstrom. Resinator wood is a wood composite material that is both more uniform in density and more stable than any standard wood product. These characteristics eliminate dead spots or wolf tones sometimes associated with conventional wood fingerboards. Resinator wood has an articulate sound similar to high quality ebony, but without any of the problems associated with ebony. It provides a stable and Clear tone, and also adds higher overtones and harmonics which uniquely detail each note. Like our H-Expander truss rod, Resinator wood is a major contributor to the distinctive Hagstrom tone.