Hi, this is an old version of the piston used in engines. look for example at set 8858 at brickshelf or at (URL) Wilson" <jonwil@tpgi.com.au> wrote in message news:3CBCBF74.401060....com.au... (...) these (...) have a (...) (23 years ago, 17-Apr-02, to lugnet.general, lugnet.technic)