The Walsco Phono Strobe Disc is a versatile accessory designed for use with turntables to provide accurate and precise speed readings for 78, 45, and 33 1/3 records. The disc features a 60-cycle strobe pattern that allows for easy calibration and adjustment for optimal performance. With a universal compatibility, this phono strobe disc is suitable for use with a variety of turntable brands and models, making it a convenient tool for audiophiles and vinyl enthusiasts looking to enhance their listening experience.It has some glue on the back maybe it had felt or rubber on it. As is no return thank you