The finial was usually found on top of a lattice post or doll, and was used by all the major Scottish railway companies (Caledonian, Glasgow & South Western, North British, Great North of Scotland) except the Highland Railway, which used SC03. Later North British and Glasgow & South Western signals used the pattern represented by SC015.

By removing the ring near the top of the spike, the casting is suitable for use on Lancashire & Yorkshire (pre 1912; use SC017 for later signals), Cheshire Lines Committee, Furness, and London, Tilbury & Southend Railway signals.