Permanent jewellery is a necklace, anklet or bracelet that doesn't have a typical clasp, the ends of the chain are linked together and then welded to make a seamless chain. The welding is a small 'zap' that doesn't make contact with the skin making it a pain free experience. The idea of permanent jewellery is that there is no intention of removing it.
They can be meaningful statements to have as a couple, friends/family members or simply just for yourself.