A pair of tongue-and-groove pliers is a must-have in every toolbox. Doesn't matter if you're dealing with plumbing, working on the car, or whatever else — if it involves nuts and bolts, these pliers are the tool for the job.

The only problem is, once you've made the appropriate size adjustment, you end up wasting a lot of hand strength trying to keep them that way. And as soon as you release the things, that effort is even more wasted when they inevitably fall all the way open, forcing you to readjust again...and again...and again...

German company Knipex, who you may know for their ingenious pliers wrench design, are also famous for their series of “Cobra” pliers which similarly use push-button functionality to easily lock in a particular adjustment. In other words, once it's set, it stays.

The jaw is designed in such a way that it can clamp well onto objects of various shapes, whether they're square, round, hex-shaped, or flat:

Also nice is the fact that the built-in pinch guard keeps the handles from coming together, so you don't have to worry about hurting your hands in the normal course of using these pliers.

They have a number of pliers sizes to choose from, with the middle-ground 10-inch pair ($42) probably being the best choice in most cases. However, you might spring for their three-size set ($113), which includes 7¼", 10", and 12" lengths.