IMP XXXXII COS XVII P P (type I, A) (441 / 450)
Bust of Theodosius II facing, cuirassed, wearing a helmet with crest and a pearl diadem. Holding a spear passing behind his head with the right hand and a decorated shield with a horseman slaying an enemy, with the left hand.
Constantinople seated left on a throne, holding a spear with the left hand and a globe surmounted by a cross with the right hand. A shield behind the throne and a star in the field to the left.
Marks

Photo of a coin sold the 19/01/2005 by Classical Numismatic Group, Electronic Auction 106, lot 277, link to the sale: https://www.acsearch.info/search.html?id=208481, link to their website: https://www.cngcoins.com/. Coin with a low weight of 4.21 grs while the wear is very low.
Variant with the letter M of IMP appearing to be a modified N. An additional stroke is seen superimposed on the right leg of the letter. There are many examples with this form, this example best showing this correction.
Mark CONOB.
Type I: with mark CONOB or COMOB (CONOB here) and the reverse legend usually ending before the shield. No punctuation on legend either side. A square throne, the right leg as a triangular protuberance, stiff drapery and vertical scepter. This corresponds to type III of RIC X. Var A is the same as RIC X: elongated and long shield.
See AYC #21, RIC 323: https://www.all-your-coins.com/en/archives-anciennes/romaines-imperiales/imp-xxxxii-cos-xvii-p-p-type-i-a-441-450, for the commentary explaining the entire coinage.