I was a tester for these strings back in 2020 and when I tried them I told Thomastik not to change a thing! I love these strings as they are easy to play and reliably sound great. They are color coded by the tailpiece and are one of my go to strings. If you feel that you need more C string strength (even though the c string is made of tungsten), try pairing the A, D and G strings  with a spirocore C string! You can't go wrong with Rondo strings.