This is a modular test tube rack system that is an improvement over my old system which you can find here and here This takes more filament and each module is taller than the old veion, but the modules snap together securely and will never slide out. Of coue they are still multi-channel spaced, as always! Let me know if anything doesn't fit well! I can adjust the dimeio if needed. IN PROGRESS: pcr tube magnets have not been designed with this veion. Please use the old veion! Included modules are: 4x4 PCR tubes (the spacing is a bit off for these. Sorry) 2x2 1.6mL eppendorf centrifuge tubes 2x2 square 2 mL cuvettes 2x2 11mm sample vials (special request!) 2x2 2mL eppendorf tubes (great for primer tubes or miniprep colum!) 2x 1.6mL eppendorf magnet rack (use 2x 15mL conical tubes 1x 50mL conical tube