Size for Adjustment: These holders are designed to enhance comfort and ensure a secure fit without slipping or constricting. They can fit different sized arms and stretch freely as you move. Well Made: Made of durable PVC and polyester webbing these arm badge holders can protect your ID cards from moisture and damage and are reusable for long-term use. Nighttime Protection: Shield yourself during outdoor activities with our arm badge holders' reflective design that glows brightly in the dark enhancing safety and visibility. Perfect for night sports or work. Ease of Use: With a transparent window on the front of the ID cards holder you can clearly see the card inside and show it conveniently for inspection.