Description: Made of Arcylic and electronic components, non-toxic harmless and durable, not as fragile as glass, long service life. Liquid Activated: This light flashing cup glows and flicker automatically when drinks are added, it turns off when there is no liquid left, it's really a cool products for drinking competition, see who is the first to finish the drink and turn off the lights Glow in the Dark Party Supplies: 7 colors flicker in the darkness with dreamlike feeling, brings your party night passion, to create an enthusiastic, charming, mysterious feeling, ideal for the bars, parties, gatherings, decoration, clubs and other dark occasions Easy to Use: Pour liquid into the flashing cup until the liquid completely covers the bottom at least, the light will start to flashing based on 2pcs powerful CR2025 batteries which could be replaced by opening the battery compartment door with a coin. Suitable scope: company welfare, bar, KTV, party, birthday party, valentine's day gift, friend gift ornament, concert, candlelight dinner, etc. Specification: Material:Arcylic and electronic components Size Chart: Capacity: 170ML/6 oz Mouth Dia.:approx. 6.5cm/2.6 inch Bottom Dia.:approx.6.0cm/2.4 inch Height:approx.8.0cm/3.1 inch Package Includes: 1 Piece lightup Beer Cup Note: 1. Please allow 1-3 mm error due to manual measurement. 2. Color might be slightly different due to the color calibration of each individual monitor.