Musiclily Pro 16mm Vintage Butterfly Style Acessório de Segurança para Cordas de Aço para Guitarra Baixo

Fairly good quality but only suitable for a bass as it is too wide for a guitar.

I'd say its a bit pricey for what it is, but I'd consider it an upgrade over the disc-style. No snagging or strings popping out.Also a plus is that it maintains a discrete, Fender-y look which I vastly prefer to ugly bar-style retainers.

I have upgraded all my basses to these. Those little circle retainers that come stock on all basses were driving me crazy, fraying the silk, getting caught up on sharp edges, strings popping out from under the circle or just moving around etc. etc.These guys looks GREAT, and have a nice smooth rounded underside with NO silk fraying or string popping while tuning. I LOVE THEM!!!!Oh, and I have a jazz bass where I needed to bring down the break angle on THREE of the strings, not just two... So, I bought two of these and put them back-to-back but staggered, so that the middle of the strings goes through two of the retainers. WORKS GREAT, LOOKS GREAT! So, SO much better than those big honking ugly 3-string retainers they sell. I spaced them out just a hair from each other so I can get a new string in between them without having to "lace it through the tunnel"... works excellent!Short answer, BUY AT LEAST ONE OF THESE FOR EVERY BASS YOU OWN, you won't regret it!Of course, if the provide screw is a little smaller than your current, you may have to fill in with a toothpick, which I did -- not a problem and the retainer is very stable.