The Casella Apex Lite is a modified version of the original Apex Personal Sampling Pump. Recently re-engineered following extensive customer feedback, the new Apex Lite features a ruggedized black plastic molded body that resists fingerprints and marking in heavy usage. It also features a thicker window to minimize accidental damage to the display. The Apex Lite is supplied with a one time alkaline battery pack for infrequent use. This can be easily upgraded to accept the regular NiMH battery pack to use with the drop in charger base for more extensive field use.