He's almost never doing this with air. Very few players at the micros will donk OTR with a missed flush. Based on his line I'd put him on something like 87s or more likely 77 based on his stats. I guess he could do it with A3 or 45 too but not as likely.

This bet size screams max value with the draw that got there on the river. I guess he could have had 88 for top set but I think he check/raises turn with top set because now there are many more draws out there. I would find a fold here unless I had some type of read on him that says he could do this with air, but I think with air he isn't shoving, he's making a bet that is an obvious value sized bet.