Measures 5-5/8" x 16-3/4" for 6-1/4" wooden frame. Our Crimp Wire Foundation is made from 100% Pure Beewax. It has Steel Vertical Wires that radiate strength throughout the entire sheet. You can get with Hooks or without Hooks. The Hooks are designed to go under and fit behind the wedge cleat of the frame to hold it securely in place. You can add cross wires horizontally for additional strength if needed. You can also use Support Pins. Foundation has deep cell walls and strong steel wires. Fresh beeswax absorbs toxins in your hive...it is a good idea to change out your combs every few years to keep your hives healthy.