From the product description, check product page for current description, price and availability:
For long term health of your elctrode use pH storage solution. It is a mixture of Potassium Chloride, Postassium Hydrogen Phthalate, Silver Nitrate, and Sodium Hydroxide.
Volume: 230 ml
Limited Availability Deal of the Day: As of this posting, this is marked down to $8.99 as a MoreBeer Deal of the Day. Shipping is also free to addresses in the contiguous US with most $59 Orders. Availability: This is available today only, while supplies last. Quantities are limited. Check the MoreBeer’s Deal of the Day to check today’s offering.
Product Description – Here – Use coupon code BEERDEAL to get this discount.