These clock inserts are *normally provided with three flexible steel spring clips as shown here which are designed to grip to the right sized aperture (58-62mm Dia). To fit into a Metalcraft design you can roll rings approx. 58-62mm diameter using steel strip to hold these inserts. Both inserts are designed take 1.55V LR-1, AM5 or UM5 or N Size or equivalent batteries (not included)
*note that due to suppliers changes the springs can sometimes be replaced by an alternative rubber gasket which works in a similar manner.”
65mm Diameter (Outer Casing) x 30mm Deep (designed to fit into an aperture 58-62mm Diameter x 17mm Deep)
Takes 1 x LR1 (keyfob) battery