This is the mrp xcg triple chain device 44 tooth bottom bracket fitting with integral bashplate mrp launches patented xcg series of impact guards for cross country bikes lots of cross country riders dont want to give up their big ring in exchange for a crank mounted bash guard nor do they want to add a large heavy bash ring on top of an outer chainring with an xcg you can keep the big chainring on and not worry about damaging it on obstacles the xcg is light weight and costs a lot les