Forged alloy steel, Quenched and Tempered, load-rated. Fatigue rated at 1-1/2 times the Working Load Limit at 20000 cycles. QUIC-CHECK markings are incorporated…Deformation Indicators check for stretch in throat opening and Angle Indicators assist users in lifting within tolerance of load angles. Chemical analysis and tensile tests performed on each batch (batches identified by PIC code located on hook). New integrated S-4320 latch (included) meets the world standard for lifting...heavy-duty stamped latch interlocks with the hook tip and features a high cycle, long life spring, may be used for personnel lifting when properly secured with supplied cotter pin.