The quality of the hardware is good, but the product is flawed. You need a high saddle on your bridge or the string break angle will be too low. Also, they advertise to be compatible with a 12 gauge set but my bass E 56 gauge is a though fit.
However, they still solve the problem they promise to solve and I have full confidence these will outlast the guitar they're on. So it's not for everyone, but it's for me!