The key with any of these labs is to send in the sample in a small box or padded envelope. Anything but the round container that hold the sample container.
But that would require the user to pay the shipping charges.... Reality is, Blackstone uses USPS First Class service and yes, they say these are typically delivered in "1-3 business days", that is a wide-open estimate
, not a guarantee. First Class mail has no service time guarantee. Anyone that complains about Blackstone's turn-around time when maybe 3/4th of the "time" is when the sample is still in the hands of the USPS is downright silly !