8mm High Resistance 'D' ShackleForged stainless steel shackles are polished to a high luster and are stamped with the screw pin diameter. High-Resistance (HR) shackles are forged in 17-4PH stainless steel to handle high loads. They have an 'HR' imprint for easy identification.Specifications:Shackle pin: 8mm / 5/16inWeight: 56.5g / 2ozMaximum working load: 2330kg / 5130lbBreaking load: 4650kg / 10260lb