Prior to this date you can identify what MK arm you have by following these guidelines.
Serial No. 1000 – all Silver and above arms post serial no. 1000 have a special damping on the tube – this was a relatively minor enhancement giving more bass depth.
From Serial No. 1023 on 13th June 2007 a packing insert was introduced which prevents damage to the dual pivot bearing if badly dropped in transit.
From Serial No. 1086 a new internal pillar style on Enterprise, and arm tube damping, respectively, were introduced.
From Serial No. 2117 a shatterproof bearing on the MK3 arm was brought in (date: 1-10-2007)