You can meet this versatile character in ISP in Jobe Market. I'd say you can't miss him, if it wasn't for his petite size. Unfortunately he's a bit sensitive about it, so unless you wish to learn a bit more about him, I advise against actually talking to him.
Most of his visitors are there because of the stuff he sells. While all of the stock can be used to build Arul Saba Bracelets, I suggest you only buy items that aren't sold anywhere else. You can get Screwdriver, Nano Circuitry Wire and Personal Furnace much cheaper in Trade sections of RK shops.
Like the rest of his stock, Unbalanced Bracelet Blueprints are rather expensive as well. Unfortunately you can't buy them anywhere else, so I suggest you bring char with high Computer Literacy to buy them (5 gem Unbalanced Bracelet Blueprints cost around 15 mill with 2k Computer Literacy).