non- corrosive and extremely durable

Months 7-12: Replace with second 5-stage filter

2 Triple A (AAA) batteries

Filter Replacement: When you notice a drastic change in water flow rate

Santevia Gravity System 5-Stage Filter 3-Pack Combo - 18-Month Supply berkey non- corrosive and extremely durableSantevia Gravity System 5 Stage Filter 3 Pack Combo Ultimate Value Get the ultimate value with an 18 month supply with the Santevia Gravity System 5 Stage Filter 3 Pack Combo. This premium bundle includes 3 five stage filters plus 1 ceramic pre filter, giving you a year and a half of clean, mineralized alkaline water with superior chlorine removal. What's Included in This 3 Pack Combo 3x 5 Stage Filters (6 months each = 18 month supply) 1x Ceramic Pre