This is a Parker 51 Vacumatic finished in Cedar Blue with a Lustraloy cap. It was made in the USA and is date coded for 1949. 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 Steel alloy 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 are no dings in the cap.