https://www.amazon.com/Lock-Jaw-Barbell-Collar-50mm-Black/dp/B01N3JWL8R/ref=sr_1_3?ie=UTF8&qid=1526435802&sr=8-3&keywords=lockjaw+pro
or
https://www.amazon.com/gp/product/B01NC0V8D4/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1
I own and love both!