Similar to its large predecessor, the Tool Pen Keychain utilizes a similar design, a heavy duty six sided barrel that houses a smooth writing ballpoint refill, hidden touch screen stylus, as well as a mini Philips and flathead screwdriver. Along the barrel you can find two mini scale functions, measuring just over 1.5 inches (or 4 cm) maximum. Perfect for on the go and ready for any job, attach to your key ring, work bag, or clipboard.