Comparison : Item # RS18-BCD, RS18 Module Full Size Metal Version Refillable Activated Bonded Carbon Disposable V-Cell Molecular Filter Filled with 60 Carbon Tetrachloride Activity (CTC) Coconut
Item # RS18-BKOHD, RS18 Module Full Size Metal Version Refillable Activated Bonded Carbon Disposable V-Cell Molecular Filter Filled with Potassium Hydroxide (KOH) Impregnated