The KORG Chromatic Tuner CA-30 is a vintage tuner suitable for various instruments such as acoustic guitar, acoustic electric guitar, bass guitar, and electric guitar. Made of mixed materials including plastic and metal, this black tuner features an auto power-off function and a built-in microphone for easy tuning. With a compact design and weighing only 2 oz, this Korg CA-30 model is a reliable and convenient tool for musicians looking to keep their instruments in tune.