Common garden variety industrial workbenches. Cannot remember the brand right off hand, I have three with that style of legs, one of another brand. The legs are a welded assembly and varying types of tops can be bolted to them. The metal tops like I have are pre punched on the bottom flange so the legs can be bolted at the joint of two tops (three legs for two tops for instance) or the legs can be set flush with the ends, or moved inward to several sets of holes. There are varying bottom shelf configurations and backboards for the bottom, back and end boards for the top, metal tops, wood tops like the one in the pic, all sorts of stuff. Tops are all the same thickness so they match up when butted end to end.
I have three of that particular brand, and one of another brand, and one 7 ft top, two 6 ft tops and one 5 ft top.
Charles