Squirrel proof Holds 3/4 quarts of shelled peanuts or wild bird food nuggets Weight adjustable to help control unwanted birds Chew proof Woodpecker friendly 2 year hassle free warranty Openings in the middle section of the metal mesh shroud align with the wire mesh holding the peanuts, providing birds access to the food. When a squirrel climbs onto the feeder, its weight automatically forces the shroud down, closing access to the ports. Squirrels and some large birds are foiled but not harmed in any way. The patented adjustable spring mechanism controls how much weight the metal mesh shroud will support, allowing the birds to feed. Any additional weight will activate the closing mechanism. The spring mechanism is calibrated at the factory to hold 2.5 oz. / 70g. It will close fully at 5.3 oz. / 150 g., shutting out the smaller Red Squirrels, as well as the larger Gray Squirrels. Note: Spring tension may vary depending on outside temperatures. Use the feeder at the factory setting – red nut on grey line – before making any adjustments. To Decrease Adjustment Setting (-) Rotate the red dial on the bottom of the feeder counter clockwise. The red nut inside the feeder will move up from the previous setting reducing spring tension. This decreases the weight required to close access to the food. To Increase Adjustment Setting (+) Rotate the red dial on the bottom of the feeder clockwise. The red nut inside the feeder will move down from the previous setting increasing the spring tension. This increases the weight required to close access to the food. Freedom to locate your feeder Now that you no longer have to worry about squirrels, you are now free to locate your feeder just about anywhere. Position your feeder over your favorite window, by your deck or in a nearby tree, for those great close-up views. Use wall brackets, branch and extension hooks to help you hang your feeder.