Aimpoint MK III Red Dot w/ Pictany Rail Mount (Very Bright) $50 plus shipping
This is an older design made by Aimpoint(not a clone). It has an oring sealed battery compartment, and includes a bikini for the lenses. It is adjustable for seven diff positions when mounting to a pictany rail. It has Aimpoint Electronic Mark III on the side, and Made in Sweden on the bottom.