Replacement hammer spring (also sometimes called main spring) for the FX Crown air rifles.
Same spring for all calibers (.177; 4.5mm, .22; 5.5mm, .25; 6.35mm, .30; 7.62mm).

Available in 2 versions:
UK Spec (12ftlb)
International / High Power (FAC) spec – 11500 – this spring is shorter but harder.

Please note fitting the harder spring may increase the power of your rifle above your local area limits.

Part number D6 on the parts diagram for this airgun.