The Mesa Laboratory Defender 530+ is a dry portable gas flow calibrator with a standardized accuracy of 1% of reading. The Defender 530+ is a direct replacement for the Definer 220 and also replaces the Defender 530. It comes in three sizes: Defender 530+ H covers 300 – 30 000 sccm, Defender 530+ M covers 50 – 5 000 sccm and the Defender 530+ L covers 5 – 500 sccm. The Defender 530+ can be used in pressure or suction mode and can interface with a PC using the free downloadable software. Process connections are Swagelok tube compression.