The Janis 13” (model CNDT) is a general purpose liquid helium 4 dewar used with the DC Field resistive 32 mm bore and 50 mm bore magnets. The useful liquid helium volume is approximately 13 liters. This volume is surrounded by a liquid nitrogen jacket. Both of these reservoirs share the same isolation vacuum space.The top inlet fitting is a 3-inch nominal ladish flange and the helium bath pump port uses a NW 50 flange. The inner tail diameter of the helium space is 0.861” +/- .005”. Helium 3 cryostats and helium 4 vacuum cans are available for use with the Janis 13” dewar.