40 or 50mm diameter Valve Disc (from £1.00 each) http://spacejockey.co.uk/back-up?share=pinterest supplied with 150mm Nickle plated chain and connector. We offer ten colour variations s for you to choose from…see Colour Drop Down. For your convenience the discs are supplied in packs of 25 sequentially numbered. (1 through 25 Inc.) (26 through 50 Inc.) etc… Frequently used Prefixes are available through the Prefix Drop Down. Manufactured from 1.6mm Impact Acrylic with UV stable colour foils. This type of product was previously known, and often referred to today as a traffolyte disc.