Pretty good. Nice that it heat shrinks too unlike standard crimps/connectors. I can say that about 1 out of about 5 connectors didn't hold tight to the wire. Might be the wire I had was a bit thin (car radio hanrnesses) but there were plenty of spares to use. Also uses a set of ratcheting chrimps. So I definitely crimped them down more then enough. Still worth the buy to me. Most likely will get them again when I run out.