This is a popular part from the Kenner Star Wars Droid Factory playset, the third leg part for the R2-D2 option. This is a vintage late 20s part, not a reproduction. If you are missing this part from your playset tray, this is the auction for you.
PLEASE NOTE: This piece was designed and sculpted exclusively for use with the R2 body from the Droid Factory playset, not the general release action figure. Thecdome on the playset droid is held in place with a double plug peg. The vintage figure has a metal screw that just deeper into the body and makes the cavity too shallow to accommodate the length of this leg. If you think it is compatible with R2-D2 or R5-D4 it is not - please do not bud. You have been informed here.