Foot mounting HNG-250 For cylinders DNG, DNGU. Size=250, Based on the standard=ISO 15552 (previously also VDMA 24652, ISO 6431, NF E49 003.1, UNI 10290), Conforms to standard=ISO 15552 (previously also VDMA 24652, ISO 6431, NF E49 003.1, UNI 10290), Corrosion resistance classification CRC=2, Ambient temperature=-40 - 150 °C