66 Place Pillar Plastic Test Tube Rack for 12-15mm Tubes, Blue (Each) Karter Scientific 400U2 Go to amazon.com Related posts Where to find tube rack 13mm? FeaturePolypropyleneRack holds up to 66 test tubes from 12-15mm in diameter Description66 Pillar Peg Test Tube Rack for 12-15mm Test Tubes. Made of plastic.