40 N2 cartridge Home Brewing Beer or Nitro Coffee Chargers 4 x 10 Nitrogen (40) https://www.amazon.com/dp/B079YM1NH6/ref=cm_sw_r_cp_apa_i_TZU4BbC94Y0KC
These are N2 charges that are in 8g cartridges but price and ship the is not as favorable as I would like.