Well, this one looks much like mine and my range is 50-120grs., in 10grn. incriments. Some will go up to 150 but miost have a max rating of 120. Just slide the outside cylinger up and down. If you wish, you could go and mark the inside cup knothches. Unless I'm mistaken, this looks like the ones sold by TC Arms, even though probably don't make them.
Be Safe !!!