Bolo Slide Lock Back 20x16mm Silver Color (1-Pc) Our top quality Bolo Slide Locks fit almost any cord size from 2mm to 6mm. Made of hardened Brass, and featuring a flip up style lock, these Bolo Clasps will give years of service. A bolo tie (sometimes bola tie or shoestring necktie) is a type of necktie consisting of a piece of cord or braided leather with decorative metal tips  secured with all clasp or slide. Sold By: Package of 1