Why do some appliances and tools only have two prongs and no grounding prong?
These products are “double-insulated” and do not need the added protection of a grounding plug. You can plug them into ungrounded outlets and still be protected. I’ve noticed that some outlets have a T-shaped neutral slot. What does this do? It identifies the outlet as a 20-amp grounded receptacle and it should be used only on 20 amp circuits.