Replacement aluminum range filters made by Filter Everything and compatible with Imperial Cal 1911. Dimensions measure 10 X 12-1/2 X 3/8/. Sold as a 2 Pack. Our filters are manuctured to meet or exceed OEM quality and are fully compatible with the name brand (OEM) model. Aluminum filters should be cleaned every 60-90 days; carbon filters should be replaced every 6-9 months. Proudly packed and shipped from our facility near Cleveland, OH.