Knucklebone - Slimini Ultem Edition
Knucklebone - Slimini Ultem Edition
Knucklebone - Slimini Ultem Edition
Knucklebone - Slimini Ultem Edition
Knucklebone - Slimini Ultem Edition
Knucklebone - Slimini Ultem Edition

Knucklebone - Slimini Ultem Edition

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"Slimini" Knucklebone

Aroundsquare knucklebones are a pocket friendly skill toy that can be manipulated to perform tricks, or just pass the time. With the original kbones, we sparked a whole new category of skill toys, but make no mistake, Aroundsqure's Knucklebones are the original hardbody knuckle rollers. The kbone "smalls" are a downsized version of the originals, packing high performance and high end materials into an even smaller, more pocket friendly unit. 

Our "Slimini" Knucklebone can best be described as a slimmed down version of our extremely popular Mini sized kbone. The idea was to try to integrate the most appealing features of all three sizes of our metal knucklebones.. slimming the form factor down as much as possible to reduce weight like the micro size, approximating the length and max diameter of the mini size for a streamlined and pocket friendly size, and maximizing the length of the grip section to make the unit easy to use for people with larger hands, and to benefit from the longer weight distribution of the original size. The resulting design hits the mark on all three. While kbone selection is ultimately a personal preference, this trim unit has a lot to offer for folks looking for a minimalist, high performance roller. The titanium Sliminis feature a comfortable machine finish that minimizes friction, along with a distinctive Aroundsquare word mark as a stamp of authenticity. 


Ultem is the branded name for a high-performance polymer also known as polyetherimide, or PEI. It's solidly in the category of what we might call badass plastics. These are materials that demonstrate exceptional properties, which truly set them apart from conventional polymers. Ultem has actually been around since the 1980s, but has only recently become widely commercially avaiable, and has subsequently exploded into the EDC scene. You'll see it in everything from knife handles to flashlights and everything in between. Part of what makes Ultem special is that when it sets and solidifies, the polymers bond in a way that prevents re-melting, even under extreme heat. This gives the material excellent thermal properties. It's also UV, chemical, and flame resistant, and due to its hardness, it can be machined very precisely, and much thinner than other plastics. Strictly speaking, none of these properties are required for a set of beads, but as with titanium on kevlar, there's just something awesome in knowing that what you have in your hand is exceptional.. that you could, if you wanted, use it for aerospace applications. The material has a crisp and solid feel in the hand. The polished versions have a glossy texture, similar to acrylic, while the machined finished versions have a soft feel, almsot like sea glass. 

To most collectors and EDC enthusiasts, the most distinctive feature of Ultem might be its appearance. It is truly something to behold. In its natural state, the material is clear or semi-transparent, with a deep golden yellow or amber colour. In fact, it looks and feels remarkably like an amber resin, and there is an interesting connection there that is worth elaborating. Amber is one of the traditionally prized materials used for komboloi and worry beads, throughout the Mediterranean and Middle East. And while we often think of traditional materials as being those that are naturally occurring, this is not entirely the case with worry beads. Amber itself is often stabilized with synthetic resins, but beyond this, readers of bead history will also see frequent reference to exotic sounding materials like Faturan, Bakelite, Parkesine, and Catalin. These are all polymer plastics - prized by antique collectors, and still used today in modern production. This historical context helps to legitimize a higher end polymer like Ultem in our product range, and in some ways, it's kind of symbolic of our journey. One of this things Aroundsquare has done well as a brand over the years is to respect and build on the historical roots of the products we create, and extend them into the modern era. We always seek to recognize and honour these roots, while bringing out contemporary designs using the best available modern materials. And having said all of that, here's this month's Ultem lineup.


  • Finish: Polished 
  • Weight: ~7.6g 
  • Length: 55mm

For more information on Aroundsquare's Kbones, visit the Knucklebone product page

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