Remagnetize if necessary. Transformers consist of 2 coils with a core piece. Either type is fine, but each station must have a complete transformer, consisting of a core and two coils. The alnico magnets are rough-surfaced and have no polarity markings on them. The alnico magnets should be stored separately from the old bar magnets.
Lenses consist of a lens mounted in an itegral holder.
Use 200mm for this lab. A few 2-meter sticks should also be set out. The eye model is a black box with a lens in the front. Check eye model for leaks. If they leak when filled with water, tighten screws.