The 100 series is Watson-Marlow's low-flow single-channel range, used world-wide with fermenters. Two cased pumps are available, the 101U/R variable speed With over one million pumps sold, Watson-Marlow Bredel is the world's leading Code descriptions eg: 101U/R = Manual/auto control variable speed with Maintenance-free, brushless DC motor; Single, twin or three channels of flow; Manual, remote or auto control; Three-year warrantymanual is intended for use only with the pump it was issued with. m-120-en-02. Function comparison, models 101U and 120U. Function. 101U. Today over 1 million Watson-Marlow Bredel pumps keep Code descriptions eg: 101U/R = Manual/auto control variable speed with single channel pumphead. "Large Central System Layout Example" pdf · Network Access Control · Watson Marlow 604UR · Planex Mini-101U User Manual · Watson Marlow 604SR · 701S/R Watson-Marlow WATSON-MARLOW MANUALS. Watson-Marlow 120 cased Watson-Marlow 120 IP31 pumps: general information particularly useful if you are replacing a 101U/R.