Hammant and Morgan Terminal Nuts. Full set for Duette. 4 Brass Nuts.
These nuts are the correct size for all H & M products.

Hornby Terminal Nuts.

These nuts are also the correct fit for
Hornby 900/901 series power controllers;
Hornby R965 controllers
Triang/Rovex PS series controllers;

Scalextric/Rovex C919 Power Units.