We have redesigned the CPO and added some new functions. It's still a versatile code practice oscillator that can be used with K1EL keyers or just about any keyer on the market. Near sine wave output with adjustable frequency and volume. A connector is provided to drive an external speaker or headphones with plenty of clean output. An on-board speaker provides a low level audio output for quiet practice. In addition a line level output is provided to drive an external amplifier or to use for internet or remote CW applications. For RTTY testing, the CPO can output RTTY mark/space tones which can be keyed using the either the key input connector or the front panel pushbutton switches. Since USB chargers are so readily available, the CPO is powered from a USB power supply through a mini USB connector. This is an easy to assemble kit including all components and a custom enclosure.