Does Ocasio demonstrate bow-flex-bow as (Rick Pauly defines it) in this clip posted by knightsb?: https://www.discussfastpitch.com/softball-pitching/24803-how-critical-brush-12.html#post429482
Here are stills from that clip (I don't know how to do height tags to size them better). Between the...
https://www.amazon.com/Bushnell-101911-Velocity-Speed-Gun/dp/B0002X7V1Q/ref=sr_1_4?m=ATVPDKIKX0DER&s=sports-and-fitness&ie=UTF8&qid=1488725900&sr=1-4&refinements=p_6%3AATVPDKIKX0DER
Not as cool as a pocket radar but you can't beat the price ($55).
I have one--it tends to measure ~1-2 mph...