The Model MRB-400, formerly named GRB-400 is a highly robust, manually retractable bollard system engineered at ASTM F2656-07 M30 (K4) standards. With a spring loaded housing, one person can easily raise and retract the bollard with less than 30 pounds of force, though an electronically operated version is also available. This product combines excellent stopping capability with an aesthetically pleasing design.