Hi , I use UR i our facility , we work with sheet metal  and I need to use detector to minimize error , because I use magnetic gripper which I can make stronger for accuracy and speed  but it gives me hard time while picking up the piece and picks up double piece or more than double , I need small maybe 0.5 inches diameter and around 1.5 inches length double  sheet pick up detector would perfectly work for me . 
I would like to have a recommendation from you 

thank you 

I guess this one can help you to understand my situation , the number  I said  is for detector , pieces are not heavy 

@kaankoyun,

As i said, a FT 300 could be installed on the UR wrist and detect the difference between 2 or more parts.
Otherwise, couldn't you simply move up until only the first sheet clear the rods then move perpendicular to the part so if there is more then one part the rods will hold it in place?