Original exam-style questions across the 4A1 subject areas, with every answer explained and the page where the topic is drawn, so you know exactly what to go back to.

Original exam-style questions across the 4B1 subject areas, from lubrication to types of plants, with every answer explained and linked to its drawn page.

One-page sketches of a boiler room tour: what each valve, gauge and control does and the routine checks, so you can picture the plant when a question asks about it.