The present invention relates to various types of garments to be worn by outdoors people such as hunters and fishermen. Also, a phase contrast electron microscope has an objective having a back focal plane, a first diffraction lens, a first phase-shifting element and a second phase-shifting element which is mounted in or in the proximity of the diffraction intermediate image plane. The dual-gate JFET includes top and bottom gates disposed above and below the channel. An oxygen generator may supply oxygen out of the housing and into the environment of the users.