Burris 1 In Zee Weaver Style Scope Rings Size:Medium Stiffened rim creates a wide Size:13D Stiffened rim creates a wide opening while climbing 25 in Width (Metric) 18 cm 18 cm Length (Standard) 22 in 25 in Length (Metric) 56 cm 64 cm Gait Women's narrow Women's narrow Footwear size range (Standard) 6 W 12 W 6 W 12 W Footwear size range (Metric) 36 43 36 43 Load (Standard) Up to 180 lbs 120 210 lbs Load (Metric) Up to 80 kilos 54 95 kilos Load w tails (Standard) Up to 240 lbs Up to 270 lbs Load w tails (Metric) Up to 109 kilos Up to 123 kilos Frame material(s) 7075 T6 Aluminum 7075 T6 Aluminum Deck material(s) TPU coated Nylon TPU coated Nylon Country of Origin Made in the USA of US and Imported Parts Made in the USA of US and Imported Parts Zee Rings (Weaver Style) are machined from a solid block of steel to exacting tolerance These rings are designed to handle any rifle and any recoil from rimfires to magnum calibers