You just can't get more Old School than a slide rule. There are a few old geezers out there who still remember how to use these things, but most of us nowadays have moved past analog computing into the digital world. Still, there was something special about the tactile feel of the index sliding gently across those logarithmic scales... So if you need to Kick It Old School, here's the nerd accessory of the year!
Technicam notitia (the technical bits
Made of aircraft-grade aluminium - strong and light-weight