Super Safeties made from 316 stainless steel. Durable, fun, and resistant to corrosion. Lots available!
If you don't know, a super safety is a FRT for AR style lowers. These ones are for a AR-15, but changing out the lever will make them work with other lowers.
https://www.youtube.com/watch?v=i1ADTvaYhY4&t=340s