Manufacturer YoYoJam
Release date June 2007
Shape Flat Rim
Color Various
Weight 65 grams
Dimensions Diameter: 53mm
Width: 53mm
Material Plastic with Heavy Gravity rims
Bearing size Size C YYJ Large
Response system Hybrid starburst/O-ring

The YoYoJam K-OS is Eric Koloski's signature series yo-yo, released in June 2007. The K-OS (pronounced "Chaos") has a shape similar to that of the Dark Magic, with a smaller diameter and flatter rims for snap starts and chopsticks-style tricks. It uses Heavy Gravity material for rim weighting, much like yo-yos such as the SpinFaktor HG and the Copperhead.

Its successor model, the K-OS Extreme, would be the last YoYoJam product to use the Heavy Gravity material before its discontinuation.


Community content is available under CC-BY-SA unless otherwise noted.