Model Number: CO2 cartridge Brand Name: DN Key Specifications/Special Features: These CO2 cartridges are widely used with fire extinguishers, there are two types, one is internal cartridge, and one is external cartridge SIZE55G75G 120G 180G ITEM NO. DN32-01 DN32-02 DN32-03 DN32-04 OD 38MM 38MM 38MM 40MM VOLUME(ML) 82.5 112.5 180 270 CO2 FILLED WEIGHT(G) 55 75 120 180 CYLINDER LENGTH(MM) 140 170 245 320 TEST PRESSURE(BAR) 250 250 250 250 MIN WT(MM) 2 2 2 2 MATERIAL 20# 20# 20# 20#