This is a Parker 51 Aerometric finished in Black with a Rolled Gold cap. Made in the USA, this is a good example of this model which dates from around 1955.
The pen is fitted with the reliable aerometric filling mechanism which has been fully serviced. It is fitted with a lovely smooth Fine side of Medium nib and is in overall good condition with light wear marks and scratches commensurate with use. The cap is in good condition with a few minor marks but no deep dings.