Several attempts at reaching seed from the Wildbill’s Feeder is all that it takes to discourage seed-seeking squirrels from returning. The feeder’s 9-volt battery (not included) generates a mild zap that repels squirrels, yet birds don’t feel a thing. There’s no harm done to the squirrels, but they learn quickly to stay away! The Wildbill’s Feeder offers excellent protection from squirrels. Capacity is approximately 10 lbs. 18 x 16 inches.