The device in the image is a Radel Dhruva Nano Zx, an electronic digital shruti box (also known as a sur-peti) used primarily for providing a drone accompaniment in Indian classical music. Key Features 4-in-1 Functionality: It serves as a harmonium-type drone, a tuner/pitch-pipe with a digital display, a metronome, and includes a built-in Perfect Pitch sruti training game. Tuning Capabilities: It features auto-tuning of primary notes (SA-PA-SA / SA-MA-SA) and allows for fine-tuning of pitch over one octave. Memory & Scale: The device includes a dual scale system (Chromatic and Diatonic) and automatically saves the selected pitch into memory. Portable Design: It is a palm-sized instrument weighing approximately 0.5kg. Power: It uses a universal voltage SMPS (90V to 260V AC) and features an automatic switchover to battery power (using ...