Locking Casters (Set 4) 3 x 1 1 4 H D Threaded Stem Trapeze Unit Single and double pumping modes 16 7136 Single and double pumping modes * Designed with leading lactation professionals the Evenflo Feeding Advanced Double Electric Breast Pump includes premium features momsare looking for * This hospital strength full time use pump helps maximize milk output is comfortable and gentle on breasts and is quiet and portable for discreet pumping anywhere * Independent speed and suction controls mimic baby This helps the user hear with maximum clarity Replacement Caster 3 x 1 1 4 * All Single Wheel Castes Come With Removable Bolt And Locknut Allowing Disassemlby For Easy Cleaning And Removal Of Build Up Grime Thread Or Anything Else That Your Wheel Picks Up During Normal Usage * This Caster System Will Add Longevity To Your Casters * Swivel: Double Ball Bearing With Hardened Raceways For Extra Strength * Cover: Helps Protect Swivel Bearings * HD Casters Have Threaded Stem For Extra Security And Safety * Construction: Heavy Guage Cold Rolled Steel Formed For Strength * Total Lock Caster Both Swivel And Wheel At The Same Time * Operates With A Simple Tap Of The Toe