Develop a passion This Dalvey aneroid barometer is a precision engineered instrument that is attractive, reliable and portable. The 4" German movement is housed in stainless steel and protected by a chromed, steel case. Two mariner maps line the interior of the case. A manually set needle allows you to track changes in atmospheric pressure. The barometric changes displayed by this accessory will draw you in over a period of time. You will quickly enjoy forecasting with this historic instrument.