5-in-1 Adjustable Dumbbell Plastic Storage Tray Included 10-Pound Increments Smooth Selector System ButSmart Adjustable Dumbbellstrikes a solid balance between helpful features and budget design. The sliding pin, for example, is simple. Its not as eye-popping as PowerBlocks color-coded plates, nor as fancy as Bowflexs numbered dial. But it gets the job done and is easy to use. In six months use, Ive experienced almost no issues. The pin stuck between plates a couple times, not locking into place. Its difficult because the mechanism isnt visible, but the fix was simple small movements back and forth until it locked in. Nothing about the design takes your breath away, but its simple and, so far, reliable. The selection of weights was also satisfying. Each dumbbellers the following choices: 10, 12.5, 15, 20, 22.5, 25, 30, 32.5, 35, 40, 42.5, 45, 50, 52.5, and 55 pounds. And each dumbbell has ten 5-pound plates (five on each side).Thats where your macro weight adjustment happens. But you can also micro-adjust weight with four smaller plates (two on each side) that add 2.5 or 5 pounds. Some brands require you to add this weight manually, but The Smart Adjustable Dumbbellshas a selector on the innermost plates. The small plastic slider pushes a cam that engages these small plates. Again, it strikes a balance between convenience and quality. Its neither the simplest nor the most impressiveering on the market, but it works reliably. Its important to note that to adjust weight you will need to have the dumbbells in the included tray. Because weights lock in vertically and by position, only the tray will properly align the plates. Frankly, this was a bit inconvenient, but its not uncommon among adjustable weights. The build is probably the biggest drawback to these weights. Nothing is as satisfying and reliable to lift (or drop) as metal. By contrast, nothing is as dissatisfying as plastic. AndSmart adjustable dumbbells feel more plastic than they do metal. The metal plates are covered in plastic, the pin selector and micro-adjustment dial are both plastic, and the dumbbell handles are you guessed it plastic. To be fair, Ive banged the weights together and dropped them from waist height onto a stiff rubber floor, and theyve held up great. But still not as nice as metal. While the brand seemed to make some concessions on the facade, the shape and design proved excellent. Our Smart Adjustable Dumbbells arecreated octagonal plates with rounded edges. This has all the balance and ergonomics of standard round plates but provides just enough of a flat surface that the dumbbells dont roll away. Unlike square plates, you dont have to worry about hitting yourself with a sharp corner during behind-the-head tricep extensions. And not only do the dumbbells stay put when you put them down, you can also use them for deep push-ups between sets.