The demountable Beta Gas Cell comes complete with a 10cm or 5cm Pyrex Cell body, cell mount, 2 Viton® O-rings or gaskets, 2 PTFE gaskets, and 2 septa, but without windows. (Windows and gaskets can be ordered separately). The window size is 25mm x 4mm. When assembled, the cell will be gas tight and operable at both reduced or positive pressures. Filling of the cell is conveniently handled with a gas tight syringe (ICL Part no. 0009-609).