38mm Double Fixed Head Wire Block. Specifically intended for use where wire lines are subjected to low running speeds and higher static loads.Body Ð Formed in stainless steel for a lightweight yet robust frame.Bearings Ð A single row of spaced stainless steel ball bearings run on a stainless steel axle. This allows the width of the block to be as narrow as possible whilst still offering excellent rolling speeds and high working loads. For faster running, lower loaded control lines consider the dynamic range.