The iMac Dark Cloth is a companion product to the iMac Shield. The iMac Dark Cloth is designed to offer a complete dark room effect when fastened to the iMac Shield. Due to the heat reflective nature of the cloth and very soft black inside these can be used to reduce or eliminate glare, protect from heat, or serve as a soft cloth wrap. The iMac Dark Cloth attaches to the iMac Shield via velcro located both on the Dark Cloth and the iMac Shield. It is available in two sizes: 21" iMac Shield Compatible & 27" iMac Shield CompatiblePlease note that the iMac Dark Cloth is sold separetely from the iMac Shieldi-Visor