The Canadian version of the QF contains a vial of crystals that need to be added to the QF after pouring into the sample cup. According to Spectrum Labs, the vial of crystals are required "to get past the additional integrity checks of Canadian drug testing".

For QF users residing in the US, the QF 4.0 is still fine as long as the batch number does not end in 05 and earlier. It is NOT necessary to use the Canadian batch.