I first purchased a translucent disc when I was doing a lot of outdoor team headshots. The light was harsh and changing throughout the session. Being able to soften harsh shadows or block the light that was making the person squint was very important.
Being a big fan of multi-use objects, I like the idea of zippering on reflectors to bounce or block light. Though standalone reflectors are also good.

My translucent disc and reflectors are both from Calumet which is no longer in business, but these seem comparable.

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