This casting represents the standard LNWR cast iron signal post cap. Dimensions are approximately 4mm high x 6mm wide.
In LNWR days, the cap was used on wooden posts or dolls. It was also used on the Cambrian and Furness Railways. After the Grouping, the design was adopted by the LMS and LNER, being used on both wooden and lattice posts and dolls.
For earlier LNWR slotted wooden post signals, use finial SC028.