Merlin and Guardian trolleys and chain adjusters are interchangeable, the only difference being which side of the pole the chain adjuster sits as this changed over the manufacturing life of the product.
Sometimes you will get them with the lever facing the door and sometimes it faces the motor, this doesn’t matter for installation, the important thing is that the pole diameter and the chain adjuster diameter is the same, so they fit either one.
Later Merlin trolleys also had an open top as opposed to the earlier closed in version, either way they all fit and operate the same.
We will supply whichever is in stock at the time.
SUITS MERLIN 230T/MT5580P/MT60P and GUARDIAN/BOSS 21230L OPERATORS.
This is a used part but structurally sound