This Pack contains 4 Plate Fitting Swivel Castors With Total Lock Brakes | The Blue Elastic Rubber Castor Wheels Range is a non marking Blue elastic rubber casters which has excellent damping vibration and noise reduction properties. Due to the material used on the tyre weight capacities can remain high.  This range will commonly be found on application which are moved on a regular basis for example production factories and flight cases for stage productions. Not sure please call our technical team before purchasing 0044 1296 431135