Caldwell Universal Standard Rear Bag - The leather gives you a secure rest and the polyester, which will not stretch or sag, allows the bag to hold it's shape. This combination makes for the best shooting bag on the market. Standard Rear Bag is for use with the 4" Center Post on the Rock(TM) and other similar rests. For use with the 4" Center Post on The Rock and other similar restsBase Dimensions: 7.4" x 5.3" x 3"Top Dimensions: 3.6" x 2" x 2.6"Furnished filled with walnut tumbling mediaWeight: 2.5 lbs