2-3/8” wide, will fit “all makes of metal bench plane”such as Stanley, Record, Footprint.

From the manufacturer, as set forth on the packaging (see photo):

Improves your bench plane.

The Clifton two-piece cap iron is an entirely effective way of improving the performance of known standard metal bench planes. The two-piece cap iron reduces cutting iron “chatter” in a number of ways, as shown on the diagram.

In essence, the hinged joint and the extra thickness mean that the cutting iron is rigidly clamped to the frog and fully supported along its width close to the mouth.

Additional features which eliminate irritating characteristics of the one piece cap iron are:

-the snug fit the accurately machine edge of the lower part of the two-piece cap iron prevents shavings being forced between the cutting iron and cap iron, so reducing choking of the mouth

– the two piece cap iron facilitates honing of the cutting iron as the lower part can be easily removed without having to lose the original cap iron setting.