Question/Answer
are these compatible with the Hach BD40 digestion block?
We have not tested these tubes with that digestion block. You would need to compare the dimensions of 26mm x 300mm to see if they match.
Do you sell the racks for these tubes?
We do not have racks to fit these tubes. We carry these as a convenience for those who have TKN blocks from other companies. They do not fit in our TKN block or rack.