Duplex Scale is available on the K-800 and K-500. Dual Duplex Scaling is an important design element that helps to make possible the beautiful singing quality of the upright piano. Duplex Scaling allows the extreme ends of the piano’s strings to vibrate and produce harmonics that enhance tone. The K-800 Dual Duplex design combines a front duplex region (between the tuning pins and agraffes) with a similar rear duplex region (between the aliquot system and the bridge) to add a double measure of harmonic richness, brilliance, complexity and sustain to the piano’s tone. The K-500 Duplex Scale uses only the front duplex region.