This is a Parker 51 Vacumatic finished in Black with a Sterling Silver cap. It was made in the USA and is date coded for 1947. The Vacumatic 51's are a lot less common than the later aerometric models and use the pump system borrowed from the earlier Vacumatic range.
The cap is made from Sterling Silver and has a gold filled clip with the famous Blue Diamond, Parkers symbol for their lifetime guarantee. The pen has been fully serviced and a new diaphragm has been fitted. It is fitted with a lovely fine nib and is in overall very good condition with wear marks and scratches commensurate with light use. There is one small ding in the cap and some light marks and scratches.