Speedball Diazo Photo Emulsion Kit is a great, fully explained, introduction to photo emulsion screen printing.

The kit contains:

7fl oz of photo emulsion;

1 fl oz of photo emulsion sensitizer;

8 fl oz of photo emulsion remover; detailed instructions. 

Please note, the bottle isn't empty, it contains a small amount (2oz) of paste that needs mixing and activating with water.