SCMR1550 15ml/50ml centrifuge tube rack 50 pcs/box 8.5 49.5 X 28.5 X 38 For 5ml/10ml/15ml Centrifuge tube. Size: 49.5 X 28.5 X 8 Qty: 50pcs/ctn Small size 15 ml 50 ml centrifuge tube rack holds 18x 15ml tube AND 10x 50ml tubes. (hole size: 16mm & 28mm in diameter). The small size holder is great to store tubes in limited spaces such as, freezer refrigerator, etc. Refoldable to save space when rack is not in use. Just disassemble it to save space. Pleasant Orange or blue colors, will send randomly We also have large size tube rack which holds more tubes (30x 10ml or 15ml tubes AND 20x 50ml tubes). We also carry centrifuge tube racks which hold 15ml tubes or 50ml tubes individually. Please check our cost effective plastic centrifuge tube racks.