Inner diameter: 2.5" Outer diameter: 3.5" These rings are twice the thickness of our normal SlingRings. They are recommended for serious weight bearing applications, like swings, ladders, or any hoisting of persons larger than infants. They are not anodized, and have a more industrial finish than SlingRings for baby slings. Base price does not include buffing, or anodizing. It is $1 each to add these services. Please email info@slingrings.com for a custom quote.