This fret contains 40 Mk1 original design autocouplings for use on 4mm scale layouts. Delayed operation is not possible with this coupling unless modified. For delayed operation, purchase AC4/3 instead.
The recommended minimum radius curve for these couplings in 4mm scale is 2′. For tighter curves, use the MP4 mounting plates. They also have the added advantage of making the couplings easier to fit.
To fit and make the couplings fully operational, you will also require BW brass wire, NSW4 nickel silver wire, SIW4 soft iron wire, and permanent (4MAG) or electromagnets (PK MAG).
The actual size of the fret is 95 x 145mm; it is etched in 0.015″ brass. Each coupling is 32½mm long and 10mm wide.