pH Meter with buffer solution, and storage box.

If you want to read up on some good information regarding pH in general please have a look at the this great post by Stephen Nilsen at Mashematics:

pH And Beer, Part 1 (Yes, It’s Important)

It is highly recommended that 3mol/Litre KCL Storage Solution (KL04183) is purchased with this pH meter. To ensure the pH meter measures accurately the electrode must be stored in KCL storage solution and the electrode must be rehydrated prior to first time use, after the electrode has been in storage for a long period of time or has dried out.