Save 15% when you order monthly—Receive the Preferred Customer Discount when you place a second order by the end of next month.*

*Requires minimum order of $45.00 (not including shipping charges). Does not apply to testing kits or environmental products, and cannot be used in conjunction with other discounts or promotions. You must order each month to continue to receive the discount on every order.

Discount is calculated automatically and may not be applied until the final checkout Order Confirmation page. You must enter the same email address used in your previous order to qualify. No PROMO code needed.