These Mini Digital Color Balance Cards are designed for the photographer who wants Color Balance Cards that can be used easily for small product photography or are readily available via a quick release lanyard. The cards measure 2-1/4 x 3-1/2".They are made of a laminated plastic that is resistant to moisture so they won't warp. This enables them to be washed with regular soap and water if they become soiled. The are flexible, 2-sided and more durable than standard cardboard cards. The lanyard comes with one each white, gray and black cards and features a quick release.