Using patented technology, the injection-molded inner bore is designed to resist cracking while also stabilizing the bore which adds consistency and durability. The upper joint body is drilled out slightly larger around the bore and tone-holes. Thermoplastic ABS resin is injected into the cavity, instantly forming the inner shape of an oboe. It is designed to preserve as much as 90% of the wooden portion, while its natural appearance is hardly distinguishable from conventional all-wooden models.
Upper-joint tone-holes (except metal octave vents) are molded simultaneously with the resin bore.
The upper joint tenon is also formed as an extension to the resin bore. This ensures smooth connection between the joints even under moist conditions.
The gold-colored trademark logo is stamped on the back of the upper joint.