This is one of two diffusors that simply snap onto the silver 5" reflectors that we have made for about 45 years. This version is the more cloudy diffusor that will lose almost an f-stop as it considerably softens and diffuses the light going through it.
Some UV light is absorbed as well so the light is softer and warmer than when direct from the reflector.
The single red cover for a Lumedyne Head jack is ready to cover one Head jack when not in use. It is one of the same ones that were included with the Classic Power Packs. It has no holes in it, so it is best sealed but it is not water proof.
This is the individual little red round cover that most people eventually lost that came standard on the Classic Packs or the ones attached with a leash to the front of the modern Packs.