It is well known that venules equipped with valves play a critical role in regulating blood flow. Essentially they are peristaltic pumps that increase the efficiency of venous blood return to the heart. thanks to the presence of valves preventing backflow. Inspired by two recent papers. https://www.spidertattooz.com/Kaiser-Copy-Stand-RS-1-with-RA-1-Arm-40-Counterbalanced-Column-and-18-x-20-Baseboard/