the appropriate cutting feed speed choice: from the cutting sparks can determine the feed speed: the general cutting sparks are spread from top to bottom, if the sparks tilt, the feed rate is too fast; if the spark does not spread and less, condensed together, then the feed rate is too slow. you won't find this deal elsewhere. whenever negative electricity flows through positive electricity, that's an electric current inside a metal. keep consistent bright lighting in all rooms. she loves to wear these sunglasses... all the time! we had a sleeper, and it was quite comfortable. part of "the great exchange" series. 