Protect fragile glass hydrometers by storing them in this 18-place rack. The middle and top plates have 1"" diameter holes. The bottom plate is 1.75"" high and has wells tapering from 1"" to 3/8"" to hold the hydrometer bulb. The base is 8.25"" x 8.5"" for tip-proof stability. Overall height 9.9"" with handles. Steam autoclavable at 250°F (121°C).