When VIVOBAREFOOT sent a care package of their amazing footwear, the Ultras we pulled out of the box were unexpected and unknown. VIVOBAREFOOT says they represent innovation at it’s best—a 3-in-1 chameleon of a shoe that’s great for beach, trail, or travel. So how did our white soccer-ball-meets-Crock Ultras perform?

Innovation and creativity really is the name of the game for the Ultras. They of course represent VIVOBAREFOOT’s extreme minimalist mindset—there’s as little as possible between you and the ground. The innovation comes from combining what VIVOBAREFOOT calls “the cage”—a perforated upper of dual-density, highly abrasion resistant material that flexes and moves very freely that you can tighten with elastic draw string—with a “sock.” Into the hexagon-holed cage, Vivo drops in a removable sock to improve fit, offer more protection, and make the shoe a little warmer for those chilly outings. You can wear the Ultra in Ultra Pure form (no sock) or with the sock liner, depending on your comfort level and activity.

An amphibious shoe, the Ultra is designed to protect your foot from injury on sharp objects while still delivering a very authentic “barefoot” feel. The sock adds to the shoe a more traditional feel—without it, the Ultra reminds me of a minimalist Crock.

However, for an amphibious shoe, I found the sock very slow to dry—if you’re going to get wet, leave the sock at home or stuff it in a pocket for after your run. Embrace the more minimalist feel of the cage (and plug-in mesh tongue insert that comes in the box) and keep the sock dry. Your foot may slide around a bit or get sand in the cage during a beach run, but it beats having a wet “sock” for hours and hours.

The sock adds a different dynamic to fit, as well. My European size 40s were snug with the sock in and a bit loose without it. The quick draw string lacing lets you tighten the cage up nicely, while intentionally providing room for your foot to expand.

While VIVOBAREFOOT says the Ultra is good for the trail, the outsole lacks the lugs and traction for rough trail running. That said, it felt sticky enough on wet blacktop. I’d say the Ultra meets two of its three categories—a beach run and travel or casual use—but is not a shoe I’d choose for the trail.

The bottom line is that the Ultras are comfortable, exceptionally light, and handle the wet well (without the sock). They squish down into nothing for travel, and if your main interest is in having a protective layer between your feet and injuring debris on a run, they’re a versatile, comfortable shoe with a unique look. Ultra’s retail for $80 on VIVOBAREFOOT’s website. That said, you could easily skip the sock of the Ultra, spend only $50 on their Ultra Pure model, and wear a pair of your own socks and still experience these VIVOBAREFOOT’s best attributes.