A Longcase, single ended suspension spring, measuring 0.15 x 6.27 x 117mm.
Manufactured in the UK from hardened and tempered high carbon spring steel strip.
Used at the top of the pendulum, the suspension flexes and allows the pendulum to swing freely.
Retain in the back cock, by riveting the single brass end through the steel strip.
The opposite end is left plain so it can be cut to the correct length, which then allows a hole to be punched or drilled to fit to the original bottom block.