Mine arrived without any sort of bracket to fit to the Large end, these should have a metal bracket that fits behind the chain wheel, the holes are in the guard for it, but no bracket included. Useless without it.
Also while the description says it's universal it wont fit chain wheels larger than 38 teeth or smaller than 32. It supports 26-28" wheels. (it doesn't have to go right up to the hub). A poor description by Amazon.
If you have a bike with 26-28" wheels and a 32-38 tooth chain wheel then it would be a good piece of kit. Providing of course they include the mounting hard ware for the bottom bracket!