Seldén Stopper Pad 523-048 is a mast-mounted support pad for fitting rope clutches or similar line-stopping hardware to a Seldén mast. The pad creates a suitable mounting surface and helps position the clutch correctly relative to the mast and halyard lead. Seldén literature lists the stopper pad at approximately 150 x 106 mm with a safe working load of 20 kN. It is intended for properly engineered mast-mounted control-line installations, so clutch size, fasteners, mast section and line lead should all be checked before fitting.