Not a LRB but quite a coin :)

[seth]

This coin is quite interesting as it's 15mm at max. diam. struck not on a small flan but rather w/ a small die and weighs 1.53g. I don't know of any other quinarii minted as limes falsi so this might as well be the first recorded:

SEVERUS ALEXANDER as CAESAR AE15mm 1.53g limes quinarius(?)/cast "falsum" (VF)

AV: [M AVR AL]EXANDER CAES; draped and cuirassed bust r. seen from back.

REV: PIETAS AVG; sacrificial implements - lituus, knife, vase, simpulum and sprinkler.

EXE: -

REF: cf. RIC IV-B 3 (but only known for denarius), rated R, otherwise unrecorded. Extremely rare. 10th of July 221 - March 222 AD.

The type is known for denarii but the dies are usually 18/19mm.