lf you feel the need for speed, the Schwalbe Stelvio is the tyre for you. On road performance, nimble and light with the added benefit of Schwalbe's Race Guard puncture protection.
A steel bead makes this a very good value tyre, if you would like something lighter with the option of being able to fold it (great for touring) then opt for the Kevlar version.
Size: 20 x 1.1/8 - 28-451

As above but with lighter weight foldable Kevlar bead. Great for touring if you want to take a spare tyre.
Size: 20 x 1.1/8 - 406

Not very interesting, but we all need them.
Presta or Schreader options available to suit sizes:

28-451 = 20 x 1 1/8
37-451 = 20 x 1 3/8
28-440 = 500 x 28A
37-440 = 500 x 28A
37-438 = 20 x 1 3/8