Dunlap is stamped or molded into the handle. There are both hex and square sockets. I think Dunlap was a Sears product. I've had this probly 60 years maybe more.
In 1965 my son was 2YO, found this set, played with it and all the sockets disappeared; read scattered all over the house. I asked him to find them cause I needed em. He did. Put em all back in the case in order. Took a couple days.