Check the listing for details. MRP chain guide, E mount, v2. Fits 28-38t chainrings.. Condition: New. Listed at 70.00 USD. New old stock! This is a brand new, in the box MRP E mount chainguide. This chainguide is good for converting your non iscg frame to have a single chainring ring retention system. This replaces your e style front derailleur and converts it to a 1x setup. This system works really well with older 3 and 2 x systems when you convert them to a single ring. Use this device also to help keep your chain on, in bumpy conditions that even your narrow wide chainring will drop. This is an e style chainguide. I’ve included a picture of what an e style mount looks like. Not all bikes have this mount, please be aware! In addition, you may have a block off plate covering up this mount. If that’s the case, all you need to do is un bolt it, and attach this.