They are very well made and the attention to detail is impressive. They insulated the outside of the clamps but retained the inside grip points in the clamps. Oddly enough, the probes they come with don't have an instruction manual, and without one you can't attach these clamps to the probes. The trick to using it is that the stylus retracts its shields by rotating the top of the stylus, exposing the threads that these clamps screw onto. I love dipsticks, but sometimes you have to click and wait. I'm surprised it's an extra charge for the sensors you have to buy, but so be it. They are worth buying.