The best way to tell is that they are functional. I've used them with 5/8" to 3/4" single wire spring clips. They have a lot of "play" between the two halves around the hinge, making it very difficult to fully compress the spring clips when the entire tool is basically twisted off. For the same price, buy the channellock version of this tool (the I own one too.) They are made in the USA and smell much higher quality in terms of fit and finish.