The RD30 is a cheap and simple commerical red dot made in China. RD30 is the model name used by BSA. Identical or near identical red dots can be found being sold under other brand and model names including Simmons, Truglo, Hatsan Optima, Barska, Trigon, and Gamo to name a few.
Images from ar15.com, commons.wikimedia.org, vk.com,