The Sightron Objective Stop Ring is designed to improve depth of field for all Sightron 60mm and 56mm models. In addition, it increases the mirage reading capability of the riflescope under certain conditions. This accessory comes in a two-piece model, allowing users to step down their 56mm or 60mm objective to either 49mm or 43mm, depending on the conditions. All objective stop rings are made to fit with or without a sunshade attached.