The SWIFF A1 clip-on tuner features a compact design. - Brand: SWIFF - Model: A1 Thank you for viewing. This is a SWIFF clip-on tuner (model: A1). It's a device used to tune instruments by clipping it onto the headstock, etc. Product Category: Clip-on tuner for musical instruments Main Uses: Used for tuning stringed instruments such as guitars, basses, and ukuleles. Tuning Method: Chromatic method, which detects vibrations to measure pitch, is common. Standard Frequency: The standard reference frequency for tuning is generally 440Hz. I used it normally at first, but the battery seems to have died after not using it for about 8 years. It has been stored in a guitar case. I have not confirmed its operation. Please understand that this is a home-stored item before purchasing.