Manually operated vacuum deivces are operated by a pump handle and vary per model. People who purchase maually operated systems generally do so because the device is easier to control and eliminates the worry of battery run down during use. Manual VED's a more reliable long term and are quieter to operate. For overall best value, check out the ErectPro Manual Device. There is no efficacy difference between manual and battery operated devices. For more information, Call Reach Medical, Inc. or contact us via the web on our contact page.