Bought a Protec case for an alto sax and thought this would make a useful additon to free up hands when there's a long walk to the bandstand. In practice, the backstrap has proved its worth many times over, either slinging the sax over one shoulder for a short walk, or using both straps for a longer route march.
Slightly fiddly to fit, but not a real problem, although the instructions could be a bit clearer to make sure you get the strap on the right way round first time.
The only improvement I can think of would be to provide some way to tidy the straps when you're not carrying the case on your back. They dangle somewhat irritatingly - I may have to improvise something with a length of Velcro or similar.
* Ceny zawierają podatek VAT. Do ceny artykułu(ów) należy doliczyć koszty wysyłki. Oferty ważne do wyczerpania zapasów. Za błędy w opisie i innego rodzaju pomyłki nie ponosimy odpowiedzialności. CK=Cena katalogowa produktu