You're welcome.
They're the Portuguese Air Force Air Demonstration Squadron.
They used to do a manouver with the T-37, which was two of them mirroring each other (one on top of the other, upside down). I was told the tricky part was because when the T-37 is inverted, it's engines get out of fuel after a few seconds (6s or 10s, I forgot which), so they had to time each move so the inverted one above, didn't fall on the other...