If you need to attach your CDs to promotional material or mailouts, CD spiders (CD Studs, CD foam button, cd hub, cd holder) are very useful. The spiders are vacuum formed plastic with adhesive backs. Once the paper liner is peeled off, they can stick onto just about anything. Some CD spiders (cd hub's) are very much like the moulded spider found in the centre of the jewel case tray and others look like small buttons (as pictured above). Available in Black, white, grey, yellow, blue, red, orange and green. They are economical and effective. Thickness: standart 3.5 mm.