The Kestrel 4000 Series Carry Case by NiteIze is a sturdy padded nylon case lets you carry your Kestrel 4000 and accessories on your belt with ease. The top flap features a hook/loop closure and a special window designed to keep the Kestrel 4000 sensors continuously exposed to the outside air, ensuring accurate logged readings. The durable elastic loop on the side of the case is perfect for carrying a small flashlight or other tool. The case also has an elastic battery loop inside securely holds two backup AAA batteries. Manufactured exclusively by NiteIze, this case features their patented J-hook made of sturdy nylon/fiberglass composite. This hook accommodates up to a 2 1/4" belt and also attaches reliably over a waistband. For complete flexibility, this case includes a strong hook/loop strap to allow for easy mounting on a backpack or harness strap.