Vibram Five Fingers KSO - Keep Stuff Out - Toe Shoes

The Vibram Five Fingers KSO (KSO stands for "Keep Stuff Out") has been one of the most popular models of Vibram Five Fingers to date (Jump to posts on the KSO below!). It's closed top design sets it apart from the open-topped Classic and the open- and strap-topped Sprint. Some might argue the KSO put "Toe shoes" on the map due to it's popularity among runners. Like all Vibram Five Fingers models, the KSO has five separated toe compartments for each toe that allow the foot to splay on contact with the ground.

The Five Fingers KSO has no arch support and a minimal amount of cushioning or padding — it is slightly thicker than the Classic and Sprint which have zero insole (the KSO has a 2mm EVA insole). Many, many minimalist runners "cut their teeth" with the KSO — running 5KS, half-marathons, full marathons, and even ultramarathons in the KSO. That said, the KSO is also a favorite for exercise, casual wear with jeans (or shorts), and also for travel.

Model specifics

Here are the technical specifications of the Vibram Five Fingers KSO straight from Vibram:

Featuring a thin, abrasion-resistant stretch nylon and breathable mesh upper that wraps your entire forefoot to "Keep Stuff Out." A single hook-and-loop closure helps secure the fit. A non-marking 3.5mm Vibram TC1 performance rubber sole is razor-siped for a sure grip, and a 2mm EVA insole enhances plating protection and comfort.

KSO IS BEST FOR: Running, Light Trekking, Climbing/Bouldering, Fitness, After Sport, Water Sports, Yoga/Pilates & Travel

The standout features of the KSO include:

  • Closed top providing a fairly tight "seal" around the ankle. The KSO manages to "keep stuff out" by way of this seal leaves it looking somewhat like an ankle sock.
  • The KSO has a 2mm insole, which reduces "barefoot feel" as compared to the Classic or Sprint. Many users don't notice this small amount of cushioning. Some find it more comfortable for more varied surfaces such as trails.
  • The KSO is the most popular model for men!

Sizing and fit

If you've never sized your foot for Vibram Five Fingers, you need to consult the Vibram Five Fingers sizing chart (image) and measure the length of your feet as presecribed. Vibram sizing does not correspond to standard shoe sizes!

If you've sized in Vibrams before, note that KSOs size slightly larger than the same size in the Classic or Sprint models. So a 43 KSO will fit larger than a 43 Classic or 43 Sprint. For this reason, Vibram prescribes you size down in the KSO compared to the Classic or Sprint models. Generally, it is better to size up if you're in between sizes — you don't want your toes bending out of lack of room! Also, the KSO's closed-top design means that if you have particularly high arches or "high feet" the KSO may not fit properly and you might consider the Sprint or the Classic. Finally, some have anecdotally observed that black KSOs size smaller than other color combinations.

Read (and see!) more about the Five Fingers KSO via these reviews:

Modifications and other considerations:

Okay, I want some KSOs. How much are they? Where can I get them?

The KSO retails for around $85 and can often be purchased with free shipping from most online retailers. Find the Vibram Five Fingers KSO in stock via the Store or subscribe by email to inventory alerts.

Of course, there are other barefoot shoes worth checking out!

More Vibram Five Fingers KSO posts below —

Tags: kso

UK Rat Racer Wears Vibram Five Fingers KSOs

Dave at the UK Rat Race
Dave walking the plank and sliding to the finish at the Rat Race.
Extreme races are the rage these days and Vibram Five Fingers fan Dave recently ran in a UK event called the Rat Race Urban Adventure. He donned his KSOs and went for it! Here is what Dave had to say:A couple pics of me from this last weekends River R… more »

Vibram Five Fingers Fare Well at the Fair

Minnesota State Fair
Click to enlarge.
Chad decided to put his Vibram Five Fingers KSOs to the test at the Minnesota State Fair. He gave them quite a workout as he describes below:I have had my Vibram KSOs for about 3 months now. I have been using them for running, biking, working out i… more »

Hiking the Garden of the Gods in Vibram Five Fingers

Andy and  Kaitlyn at the Garden of the Gods
Hiking the Garden of the Gods in Vibram Five Fingers
Pictured above in their Bikilas and KSOs, Andy and Kaitlyn visited the The Garden of the Gods on their recent trip to Colorado. Andy gives us the details below:Hey! My name is Andy and recently my girlfriend Kaitlyn and I went to Colorado to visi… more »

Five Fingers KSOs in the Klondike

Phillip on Chilkoot Trail
Phillip looks back into a valley and some rocky terrain on Chilkoot Trail.
Phillip, a Vibram Five Fingers fan, and his girlfriend recently hiked the Chilkoot Trail in Alaska and British Columbia. This trail was used by prospectors during the Klondike Gold Rush to reach the Yukon goldfields. It is a 33 mile trail that can takes… more »

Gardening in Vibram Five Fingers KSOs

Jason Gardening in KSOs
Jason Gardening in his KSOs
Jason sent us the following message about his search for the perfect gardening shoe:I've finally found the perfect gardening shoe! I am an avid gardener and have spent years trying to find a shoe that was able to meet the demands of gardening. I tr… more »

KSOs on Killer Hill!

Millikan at Morgan's Little Miami Triathlon
Millikan running up the final 50 yards of Killer Hill and other race pics.
Millikan recently wore his Vibram Five Fingers KSOs in the what is billed as the oldest triathlon in the continental United States. With two man teams and canoes it is certainly one of the most unique triathlons. Sounds like fun! Here is a description of… more »