Thimbleye Eyelet, For 5/8" Thru-Bolt, Not Threaded, Straight Eyelets are also know as Eye Nuts, Guying Eyes, and Eyes. Eyelets come as a Tripleye, Singleye, Oval Eye, Thingleye and more. Eyelets are used under the head or nut of a bolt and attach to a Thur-Bolt on a pole for guying Utility Poles. Thimble eyelets are used for span guys and oval eyelets are used for deadening. Both eyelets have a slotted hole for ease in inserting a bolt. Made from galvanized steel.