An improved an accessory mounting arrangement for an internal combustion engine that allows a low mounting position without overstressing the oil pan that provides a part of the support. A generally C-shaped trocar provides increased work space between the hands of the surgeon as well as S-shaped laparoscopic instruments placed through the trocar when laparoscopic instrument-trocar units are placed through the umbilicus. The magnetic strength of a first magnet arranged on the first movable member exceeds the magnetic strength of a second magnet arranged on the second movable member. The heat transfer system is capable of transferring heat between the first surface and the second surface.