Rapid ECH0730 Test Tube Holder is an economically priced, maximally functional plated spring steel wire holder with finger grip. The jaws will accept tubes up to 40mm diameter and their alignment is maintained by a wire collar. Overall length 6.5". * Quality plated steel wire test tube holder * Finger grips for comfortable and secure use * Self closing clamp for ease of use * Lightweight and, space efficient * Durable enough for student use in the classroom or lab