I ordered the shrink tubing in 2 sizes. After the complete installation was completed and the functional test was carried out, I wanted to shrink the previously only loosely pulled on shrink tubes and seal the connections. With the heat gun on the highest level, there was hardly any shrinkage. So I bought a hot air gun and checked the temperature, unfortunately no shrinking!? When the plastic hoses were about to char, I broke them off because I didn't want to damage my electric cables!! My Comment: Total scrap for a lot of money! So far I have always been satisfied with SVB, but unfortunately my complaint with a request for a return or exchange was unfortunately not answered! I will probably turn to another provider in the future, although I have left a lot of money with SVB in the last few weeks!