ABB VEM4 — is a mechanical and electrical interlock set for the interlocking side-by-side without additional width of two AF09. AF38 or AFC09. AFC38 contactors.VEM4 set includes a mechanical interlock unit VM4 with 2 fixing clips (BB4) and a VE4 electrical interlock block with A2-A2 connection.Fixing the electrical interlock block on the front of the contactors connects the 2 built-in N.C. interlocking contacts to the two coils saving up to 50% less wiring compared to conventional electrical interlocking.VE4 block must be used with A2-A2 connection to respect the electrical connection diagram.