Watch List notes:

Carausius. Romano-British Emperor, A.D. 287-293. AE antoninianus. Mint uncertain and/or unofficial. [IMP] C CARAVSII IN AVG (sic.), radiate, draped and cuirassed bust of Carausius right / [PA]-X AVG, Pax standing facing, head left, holding olive-branch and vertical scepter. Cf. SR ('88) 3568; Cf. VM 24. NGC Choice XF, somewhat off-center, crowding obverse and losing some reverse legend, faint scratches reverse, dark green patina with a few red spots.

with the exergue off-flan and no field-letters on reverse, plus the irregular obverse legend, it's not possible at the moment to assign this to a mint with certainty, but I suspect it's from Camulodunum