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.
Response view (silicone'd)
This K-OS was modified, Dyed, Rims painted black, shimmed and silicone'd (By JPM). Photo Taken By Jeffrey Pang