100% compatible with each other and designed with zero tolerance, the two-part BASIS® system connects every weapon model with the respective target optics with absolute reliability. With really 100% reproducibility, you can use multiple target optics safely and easily on each of your weapons. Once adjusted, the mounting rail always locks to the base rail with the same torque and without play. The once queasy feeling after putting your optics on and off is a thing of the past, because the BASIS® gives you, as a hunter, real confidence in your tools.