I'm sure others will chime in for you. A thumb would be a nice add-on for almost any box, making it a lot more versatile.
But here are some things to consider on the item. Don't jump to choose price over quality. Know what you are buying. First, the type metallurgy can make a big difference in how strong it is. You don't want to see it bent after clamping down on a log. Someone here will know the correct metallurgy to use. You may also want to ask about the welds. Next, does it use bolts/nuts or pins for the pivot points, and are there bushings and grease fittings. If it has bolts/nuts (least expensive) it will wear much quicker than pins with bushing & grease fittings. The cylinder looks like the tie-rod type, which is the least expensive type available. This would probably be OK for occasional use, but not for daily wear and tear. Ask about the painting too. Simple spray painting w/o primer may look OK, but won't hold up. Powder coating would be much better.
This should help you decide. Talking with someone who has one of these exact items would be great. You might be able to contact some previous buyers through the sellers feedback.
