AT6181DL Stroboscope Disc and Quartz Strobe Light Stroboscope disc and light kit Exclusive flashing light pattern to measure 78 RPM Yellow LED light for accurate reading of 33 1/3, 45 and 78 rpm speeds The AT6181DL kit includes a stroboscope disc along with a quartz strobe light, giving you everything you need to precisely check your turntable's rotation speed. The light’s yellow LED provides a clear, accurate reading of the stroboscope’s high-contrast markings for 33-1/3, 45 and 78 RPM speeds. Stroboscope disc also includes an overhang guide.  Specifications   Stroboscope Disc   Speeds:  33-1/3 RPM, 45 RPM, 78 RPM  Dimensions:  104 mm (4.09") diameter  Weight:  35 g (1.23 oz)  Strobe Light   Frequency:  33-1/3 RPM, 45 RPM: 120 Hz 78 RPM: 234 Hz  Battery:  AAA (alkaline or nickel-hydrogen) × 2, sold separately  Battery life:  Approx. 8 hours (continuous use)  Dimensions:  32 mm (1.26") W × 19 mm (0.75") D × 115 mm (4.53") H  Weight:  35 g (1.23 oz), without batteries