That'll be the F35. They're using the C variant though, which can carry bigger payloads than the B.
I doubt many, if any SAM sites can lock onto the F35 in a real world scenario though, it's like saying a submarine has sonar sensitive enough to detect a ship in New York - it could, if it weren't for the other million ships, billions of fish, a few whales having a chat, underground seismic activity etc etc etc. Can it pick up something with the Radar Cross-Sectional area of a marble? Maybe. Can it detect that marble travelling at Mach 1.6, at 50,000 feet? Unlikely.
Likely as not they'll only get a lock when the payload bay doors open - which is about a second before the bomb/rocket is released. At which point it's a bit late.
Even if a SAM site could get a lock, it wouldn't matter because it'd probably have already been hit by Tomahawk by the time the F35s show up, like happened in Libya.