Single tire lever, plug kit, CO2 and inflator wrapped inside the tube, strapped to the frame.
I haven’t had to tube a tire in years now. I still carry one on big XC events and rides. And since my E29 has the SWAT box I keep one in there too, but that has been in there for 4 years now (just inspected it, still good). I have had to plug tires though, and CO2 gets me going.