The CTI Ozone machines are the Most Powerful, Efficient, Economical, and Simple machines on the market. These machines are a favorite of restoration professionals with proven reliability from years of on the job performance. These machines come with a plug in timer and should not be run withoiut one. Their operation is simple just plug it in, set the timer and go. Machine Size is 5.5 in. X 5.5 in. X 18 in. Service for the machine is simple and reliable. Just send it in with a $45. Co pay and it is repaired or replaced no questions asked.