The Seed No Mess from Bonka Bird Toys is a great durable clear plastic feeder for your small sized pet bird. This feeder has a straightforward design appealing to birds and owners alike with the added benefit of being able to be installed inside or outside of the cage. The looped hooks can be installed on the front or the back of the Seed No Mess with small eyelid holes. The hooks each measure about (1) inch in length and can easily hook around most smaller cage bars. When installing the feeder be sure to place it in a secure safe place. When properly installed the feeder should be stable where it is and comfortably hold your pet and whatever is on the menu! The plastic feeder holds (6) ounces of dry food easily and can also hold liquid. In the first bay there is a laser cut bird friendly perch. This perch sits within its own bay staying clean and neat for your pet. All of the seeds and food they eat will stay inside of the second bay making cleanup easy for everyone! The measurements for the Seed No Mess are as follows: Feeder - W: (5) inches x D in middle: (4.12) inches or (1/8) inches x H in middle: (5) inches Main opening - W: (4.81) inches or (4 13/16) inches x H (3.12) inches or (3 1/8) First Lip: (1) inch Food Bay Lip: (1.5) inches or (1 1/2) inches A great easy to use small size feeder. Comfortable for pets and easy cleanup. Strong durable plastic. 100% bird safe.