The MA-30 is the latest offering from Korg's innovative line of metronomes, with new features like volume control and sophisticated rhythms such as triplets and quadruplets with inner beats omitted. Highly visual liquid crystal pendulum. 13 different rhythms are built-in so you can practice to more than a click track. Rhythms include duplets, triplets, triplets with inner beats omitted, quadruplets, and quadruplets with inner beats omitted. Twelve reference pitches 4 -B4 for you to tune to. Adjustable calibration (438-445 Hz). Adjustable volume. Tempo adjusts from 40-208 bpm. Tap function for setting the tempo. Earphone jack so only you can hear it. Memory backup function. Approximately 250 hours of continuous use.