The Safe+ Hit Personal Alarm from Unikia puts peace of mind right on your keychain. It features a plastic tube that has a built in audible alarm that can be activated with a press of a button. If a weapon is required, a quick yank of the attached key will turn the tube into a handle with the key as a blade. The Safe+ Hit is available in black or white and uses uses 4 CR2032 batteries for the alarm. You can buy one now for €15.96 + €9.60 for international shipping to the US. That comes to $34.01 in US dollars.