Brewmaker  Heating Tray  for 4 demijohns

The top face is 37.5cm square, which is perfect to take four 1 gallon demijohns, and it is tough enough to take the weight without sagging. 

It is strongly made from flame retarded injection moulded polycarbonate, is splash resistant and being rated at 40 Watts is powerful enough to raise the temperature by about 5C whilst still remaining economical to run.