This is an example of the first variation of the 300 model. In 1930 they were marked as model 826, but this was obviously too much for Petromax so they changed the number for 1931. Otherwise there is no difference. There are several things to note on this first variation. The vaporiser is in one piece and the cleaning needle rod is accessed through a plug in the bottom of the vaporiser. The mixing tube has two parts with a different diameter and thread. This is almost identical to the very early Petromax 826. The pump knob is a large diameter, about 25mm. The filler cap has high wings. This example is in poor condition, but rather one in poor condition than none at all.