They say:

The Ibanez NU TUBESCREAMER is the very first compact guitar electronics_effects pedals to incorporate a Nutube directly into its circuitry. This pairing of Ibanez's Tube Screamer with KORG's Nutube technology, has produced an overdrive with exceptional dynamics, improved sensitivity, and natural tube compression.

*KORG and Nutube are trademarks of KORG INC.

•Controls: Drive, Tone, Level, Mix
•Size: 71(W) x 124(D) x 53(H)(mm)
•Power Supply: DC9-18V (Negative Center) or one 006P 9V battery
•Current Draw: 50mA@9V, 60mA@18V
•Development collaboration with KORG Nutube
•100% Analog circuitry
•Relay True Bypass Switch
•Made in Japan