turbo fittings

Hi i have just recieved my turbo back from being rebuilt and the firm have taken the fittings off for the water hoses and the oil return hose and havent put them back on. They have left me with a bag of bits to put back on the turbo but im unsure on one thing. There is a part that looks like a bearing about 20mm in diameter with some holes drilled around the edges of it. am i right in thinking that this part goes into the oil return fitting underneath the turbo before its bolted back onto the turbo and acts as some kind of reducer for the oil? appreciate any help thanks

you may have to put a picture up. - it sounds suspiciously like something out of the inside a turbo?

is it the old bearing from your old turbo?