No8(4.00mm) Carriage Clock Key.

No8 Popular Progress, high quality Carriage Clock Key. Manufactured from solid Brass, with a deep winding square, & thicker stronger handle. Ideal for French clocks, Carriage clocks, & Wall Clocks fitted with an  adjuster pipe of 2.1mm on this size of key. All of the key is manufactured in our workshops in Derbyshire England.

 The size listed refers to the distance between the flat section inside the winding square