Hi, here are some photos of a Primus No.85 that I have just fettled. This is a 3.2 litre/5.67 UK pint capacity paraffin-fuelled furnace intended for industrial use. It burns about 1.6 litres/h and I estimate the power at 16Kw or about 55,500BTU/h. In the last photo the Primus 85 is shown alongside a Primus No.96 to give some idea of scale. Best Regards, Kerophile. NOTE; This particular example has been fitted with an equivalent Monitor (UK) burner.