[Paduan (Brett)]

hi this may sound stupid but i have a thing that fits lots and is useful for nothing i believe that it is some sort of imaging barlow but it only fits an old Yashika screw mount adapter. it came with a second hand C8 i purchased. looking through it ,it appears to halve the image size, as in not 2x but 1/2x i have screwed it in to my 8x50 finder and i cannot focus it i have added some pics of the ends. please excuse the dirty fingers i am working on the car