Cluster Bar Collector Assemblies. 30 Amp Compression Collector, 14 mm Two (2) Insulated Contact Heads Mounted on Self Centering, Spring Loaded Arm Assembly that Articulate. Exposed Metal Surfaces on Collector do not Carry Current. Sliding Contact Type Confines Wear Only to the Easily Replaceable Contact Shoes. See Replacement Shoe # 28082 Collector Arms are Designed to Accommodate a Certain Amount of Movement or Misalignments Between the Crane / Vehicle and the Conductor. However, if Misalignements are Excessive the Collector Could Disengage from the Bar. Poor Collector Installation is the Single Greatest Cause of New System Problems. Installation Instructions Should be Closely Followed to Optimize System Performance and Prevent Problems.