This coin is part of the extremely rare and sought-after coded AEQVIT series (issue 7 according to Pink's classification), which is many, many times rarer than the popular EQVITI series (issues 8, 9 and 10 according to Pink's classification).
The code consists of the consecutive letters of the word AEQVIT placed in the left field by the six workshops (officinae) operating at Ticinum under Probus. Each workshop placed only one specific letter assigned to it. This coin - with the letter "V" in the left field (i.e. fourth letter of the code) - was struct by the fourth officina (officina "Q").
For more information about the (A)EQVITI series see the below excellent article by Gert Boersema:
http://www.oudgeld.com/webbib/translation_codewords.htm
Perfect mint condition with excellent details and full silvering. Exceedingly rare in such a magnifiscent state of preservation! One of the best preserved coins of this great Probus collection.
OBVERSE: VIRTVS PROBI AVG
REVERSE: MARTI PACIF
BUST TYPE: E1 = Radiate, cuirassed and helmeted bust left, holding spear and shield
FIELD / EXERGUE MARKS: V/-//QXXI
WEIGHT 4.81g / AXIS: 1h / WIDTH 21-24mm