Review on Enhanced Flexibility with Piece Flex Head Flare Wrench by Carl Givens

I use it professionally and have never had an open or broken jaw. The hinge pin feels strong. The shape of the hex heads gives you the advantage of being several degrees in front of or behind the fastener. In tighter spaces I'd like another 5 degrees or so, but that's not a deal breaker. The turned hex hole also gives you more wrenching over the tiers of the fastener than the old Craftsmen, Pittsburgh Pac-Man style sockets or even the more expensive Gear Wrench set. The heads are thinner than those sets. They're as thick as any brake line fitting I've put them on so you don't lose any contact area either. Very handy for working clutches and hidden master cylinders.