"It may be the smallest vacuum tube headphone amplifier in the market".
By using one piece of Philips JAN 6111WA vacuum tube, with selectable sound field effect, iH is perfect to drive any headphone with impedance from 32 to 300 Ohms. High accuracy components used in iH is the main reason why it can out-perform most of the same products in the market. Rechargeable battery can provide 6 hours non-stop entertainment after fully recharge. Prestigious casing using high grade 7075 aluminum, carefully craft to shape by CNC, and special treatment on the surface.