SPECIAL FEATURES OF THESE BLOCKS:STAINLESS STEEL BALLS RUNNING OVER STAINLESS STEEL RAILS RESULT IN A HIGH CAPACITY AND PERFORMANCE FOR A SUCH A COMPACT PRODUCT.COLD FORGED RADI-[USED HEAD INCREASE ARTICULATION , IS KIND TO ROPE END SUPER STRONG DUE TO THE DOUBLE CURVED DESIGN .LIGHT OPEN AXLE ALLOWS ROPE TO BE TIED TROUGH NEGATING THE NEED FOR END ADDITIONAL BECKET .FULL MOLDED JACKET PROVIDES SHEAVE PROTECTION FOR HARSH RACING ENVIRONMENTS.Working Load 300 Lbs Nautos HT 2021 HK - 20mm SHEAVE BLOCK WITH HOOK - BALL BEARING  ROPE PULLEY