Yes, it is a Kit of 3 sticks, Corsair, 2 MB each, 1333 MHz, the part number is CM3X2G1333C9, seated in DIMMs 0, 2 and 4. If either stick is bad you will need to buy an entire kit, that is very true.

IMHO it will be wise to make it sure that neither of the DIMM slots are bad. But it is your computer. If you think you may avoid it, no problem.