Rolltek is a leading supplier of Flight Case Castors.  We offer a medium duty bracket with an overall height of 125mm and a heavy duty bracket which is the ‘industry norm’ with an overall height of 132mm.  However, if you are replacing castors then you will need to check the overall height (distance from the floor to the top of the bracket) to be sure of which size you require. Both types of castor have blue elastic rubber tyres, these are quiet running, non-marking and provide the user with a soft, smooth cushioned ride.  The Blue Elastic Rubber provides a higher load capacity than a standard rubber wheel and gives a good wear resistance.  All the wheels have roller bearings and are fitted with matching blue elastic thread guards. Please look at website under part no RT4LPBLU (Swivel), RT4LPBBLU (Braked) RT4LFPBLU (Fixed) for Medium Duty and RT4VVPBLU/S (Swivel), RT4VVPBBLU/S (Braked) RT4VVFPBLU/S (Fixed) for our Heavy Duty Castors or click on the relevant part number required and this will take you to our website for this part.