This is a Parker 51 Aerometric finished in Black with a Rolled Gold cap. Made in the UK, this is a very good example of this model which dates from around 1960.
The pen is fitted with the reliable aerometric filling mechanism which has been fully serviced. It is fitted with a lovely smooth Medium nib and is in overall excellent condition with only very light wear marks and scratches commensurate with light use. The cap has one very small ding.