Are there different kinds of trumpet valve guards?
There are many types. A handerchief is a valve guard of sorts.
There are vinyl, leather, plastic, neoprene.
There are valve guards made of multiple materials, i.e. leather exterior and man-made materials for contact with the trumpet. The can fasten on with snaps, laces, velcro.
There are many different manufacturers although
Bach, Protec, Reunion Blues all market trumpet valve guards.