Cage itself is 2.5 inches. 2.8 from back of single ring, 3 from back of double ring. ID 1.25 inch 1 3/4 oval single ring 1 7/8 oval double ring Both rings with extra hole for security lock or tag 3 plastic locks. 5 punishment pins. Only 1 security screw & key Bought it here on CM a couple years ago, overpaid at $425. SELLING for $350 Been a pretty awesome cage