The Avalon X-Guider is a mechanized dovetail for guiding systems. It is adjusted by two easy to twist and grasp knobs, allowing you to raise or lower the plate to adjust your guide scope. It has a payload capacity of 6kg (13lbs). It may be locked into place once you have the correct position. For Further Data, Please contact us at 800-483-6287. Due to minimum shipping restrictions from this manufacturer, lead times for Avalon accessories will vary. Please contact OPT for details.