I'm not a professional drummer so I can't make any comment on how well they stand up to a 12 hour paradiddling session but I can say this - they're basic, nylon-tipped drumsticks that outlasted the stock pair of wooden ones that came with my electric kit.
As a three component bit of kit (plastic, glue, wood) there's very little to say about these sticks apart from the fact that they're very good value - I'm an amateur so I can't really see the difference between these and a pair of sturdy Vic Firths hewn from a mighty, ancient oak tree tipped with age-depositioned Jesus tears.
I've always found Thomann's Millenium branded gear to be of decent quality without hitting me too hard in the pocket and these are no exception. If I had the inclination or space to play drums again I would probably buy another set of these (that is assuming I couldn't find and dig out my original pair).