Warner #2 rear sight, Match Rifle direction, 1/4 MOA, 40 TPI fine click, with aperture. Aperture is probably a Gehmann 510 but I can't identify it for certain. Sight has been milled for clearance on the bottom- see pic. Milling will not hurt the function or mounting to the base. $675 Sight is on consignment and any offers will be presented to the owner for a decision. Best contact is whiddengunworks@yahoo.com