Custom assembly of custom avionics, military and space power systems of others; custom manufacture and custom assembly of semi-conductor devices, namely, transistors and diodes; Electric power converters, namely, DC-DC power converters, point of load (POL) power converters and high reliability commercial off the shelf (COTS) power converters; electromagnetic interference filters for filtering high frequency noise and electromagnetic interference transient voltage suppressors; accessory power-related products, namely, inrush current electricity limiters, thermal pads, namely, DC-DC converter cooling pads, pre-conditioning voltage monitor modules, and high voltage electric bus converters; Catalog ordering services and on-line retail store services featuring products directed to the avionics, military and space power systems, namely, power converters, electromagnetic interference filters and suppressors, accessory power-related products, namely, inrush current limiters, thermal pads, pre-conditioning modules and high voltage bus converters; Custom engineering services and product testing services, namely, the design and product testing of custom avionics, military and space power systems; electronics product testing services, namely, conducting environmental, burn-in, static and dynamic testing of discrete, linear, digital and passive electronic components and devices