Can anybody confirm that this photo I took is showing the engine block coolant drain plug? (with the hex shaped recess)

Location is driver's side, near the front of the engine, around cylinder #1, below the head.
You can't see it from under the hood because it's hidden by the power steering pump (the hard lines in the photo), and the flange of the head. I took the photo from underneath.

What size hex bit is needed?



Vortec 5.3L (LMF)
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Good thing I didn't try to remove that one, because it's an oil gallery drain plug. The coolant drain plug is a little to the right, but it's inaccessible, because the front axle is about an inch in front of it. I guess I won't be using it when I change my coolant.