Soldering irons with sponge included

Sponge

— the presence in the delivery set of the soldering iron of a special sponge for cleaning the tip from all kinds of deposits: flux residues, solder, etc. Cellulose sponges are widely used, porous viscose sponges and metal shavings are slightly less common. However, the last option is already the subject of a completely different conversation (see the “Tip Cleaner” paragraph).