The Rock Exotica OMNI BLOCK SINGLE® is a mix of the old and the new. The Rock Exotica Omni Block Single is a high strength 1.5″, swiveling rope block/pulley. This pulleys eliminates twisting from rope rigging systems with smooth, ball bearing action. The precision fabricated alloy block has a unique button-activated release feature that allows instant access to the sheave for midline attachment. The milled alloy attachment eye is large enough to accept most carabiners and snaps. Made in the U.S.A.