The Black Scorpion double-sided Allen Key is specifically designed to provide a perfect fit for the screws used in the Pro Heavy Duty Competition Holsters and Pro Heavy Duty Competition Speed Holsters. The 2mm short side is tailored to the 4x belt attachment Allen screws, while the 3mm long side is ideal for the rear Allen screws. With this tool, you can easily and efficiently make adjustments to your holster without any hassle.