The Merkmark Electric Heating Pad works perfectly and is advantageous to my needs. When one has a painful ball of pain riding one's back any heating pad that can fit without making thing worse is perfect. The heating pad curves on my back perfectly. It does not bunch up like the previous one I owe. It is so thin one can barely feel it when laying on it. I can lay down on the pad without discomfort. The heating pad came well-packaged in a small box. Size is 12"x24" It is hand and machine washable. I have not tried to wash mine yet. It has an ON and OFF switch that contains the control for HEAT and TIMER. It has 6 temperature levels setting and 4 timer level with 30/60/90/120 minutes increment. I definitely recommend the Merkmark Electric Heating Pad.