Unfortunately, Rob does not have custom boxes for his speakers, but each pair will be packed in a removals box. Dimensions are 450mm x 250mm x 85mm. Grilles add an extra 10mm or so. Note that this is for a pair of speakers, and I have two pairs available.
The speakers are about 5kg each and the box works out as about 15kg with both speakers. Please note that although some photos show 4 speakers, the price is for a pair and two pairs are available.