Product arrived just over a month after placing order. Unfortunately the emf canopy had been damaged (presumably by customs)with the netting material being sliced through multiple layers...not happy. I had to stitch close the holes in the canopy. It does block wifi..to a degree. I can still run my laptop inside the canopy while it is fully enclosed with a ground sheet, with no loss in wifi signal?? So it does still let wifi through. My phone drops two wifi bars and there is no change to 4g reception from phone towers whilst inside. So in conclusion, I would say it is better then nothing, but not as good as some other emf/rf sheilding material out there.