Contact pickup for Matrix tuner. Operation confirmed. This is attached to the body of an instrument with a suction cup and used by connecting it to a tuner. While it can function as a pickup, it's best not to expect high sound quality. The product is labeled "Acoustic guitar tuner pick up," but it is likely usable with various acoustic instruments such as ukuleles. *Please note that this item is also listed elsewhere, so it may be sold out due to a timing difference.