The Strike Industries Multi-Function End Plate and Anti-Rotation Castle Nut are designed to be a secure system that can adapt with you. The MFEP and CAN offer a built in anti-rotate QD socket (sling loops). These two parts are made to function together. Instead of peening the endplate to secure the castle nut, a set screw allows for multiple uses as you upgrade your build. The MFEP is reversible and is equipped with three integral mounting options: a traditional sling loop, a loop for hook style attachments, and a QD socket. This gives you the flexibility to mount attachments to your own preference.