The Sig Sauer ALPHA1 Steel Hunting Rings comes in six models/sizes. They are either 30mm or 1 inch diameter and come in low, medium or high mounting heights. They fit 1913/picatinny rails.
Torq Specifications for Alpha Hunting Mounts
To Rail (T15-TORX): 25in/lbs
To Scope (T15-TORX): 25in/lbs