I found the information below by reading the product information sectection. For more information, Presma has their own website. My quick look at their site also said it take 70+ ft/lbs of torque. That should cover most installations.
Specifications for Presma AR-15 .223 Barrel Vise Block Rod w/ Torque Block for .750 Barrels:
Finish: Anodized
Fabric/Material: 7075-T6 Aluminum, 6061-T6 Aluminum
Quantity: 1
Caliber: .223 Caliber
Gun Model: AR-15
Gun Type: Rifle
Length: 11 in