J Bolts for concrete don't have a head on them. The bent part is embedded into the concrete and would never be turned. Forming a hex head would be a wasted extra production cost.
Even with a washer, the head of a straight bolt won't hold very well in concrete when you go trying to tighten it, it'll most likely start spinning and possibly even damage the concrete.
That is one of those right angle bolts for getting into tight places. Hang onto it because they cost about $15 each new. It is specially made to transfer the torque from the head around the 90 degree bend. Just line it up with the nut, slap a driver on there and go to town. I promise, it will be amazing and nothing bad will happen.
These bolts are like this from the factory - I have 4 on my honey extractor, they are used for other situations where you need to bolt one thing perpendicular to each other.