Custom Hydrogen Generator Bubbler Tank - Large With 3/8" Fitting Made Of Durable See Thru Plastic Filters Debris Down To 1 Micron ~ Cleanses Contaminants Such As Potassium & Sodium Hydroxide, Baking Soda etc. Prevents Flashbacks From Entering Your Generator 10" Tall & 4 1/2" Diameter ~Also Available - 5" Tall ~ Different Fittings Available On Amazon 1/4", 3/8" & 1/2" Ships USPS Priority Mail (More than 1 Unit May Ship Standard)