Bel-Art F18745-0004 No-Wire Test Tube Rack; 25-30mm, 21 Places, 9.7 x 4.1 x 2.5 in., Polypropylene, White For 30mm Tubes; 21 places - 3 x 7 rows Rack dimensions: 9.7 x 4.1 x 2.5" (24.6 x 10.4 x 6.4cmH) Features end plates for easy labeling and lettered and numbered rows for tube identification Durable, white polypropylene rack is submersible in a water bath and stable in agitated water Assembles in seconds, can be stored flat or stacks with interlocking feet