The IQD Quartz Crystal is a industry standard SMD crystal resistance welded, hermetically sealed in an inert atmosphere, glass to metal seals on leads lead wires are mounted onto a plastic former to create a gull wing mount.Frequency is 4.0MHzFrequency tolerance is ±30.00ppmTolerance condition is at 25°C ±2°CStorage temperature range is -55°C to 125°C