Doesn't work - SightMark SM26017 Core Shot A-Spec FMS 1x 28x18 mm Obj 5 MOA Illuminated Red Dot

Ordered one in early June off of Amazon would not turn on when I received it send it back have three of sightmark ultra sights really wanted a core shot ordered one mid-october from opticsplanet received it same exact thing brand new would not turn on sightmark customer service took six phone calls before I talk to someone said they would replace it if I sent it back to them but they had none in stock and didn't know when they would receive any do not buy one