Kingston ram

Well me thinks it may be time for glasses....

I am building a new system and the ram I purchased is:

Kingston
8GB Module - DDR3 1333MHz
Part Number: KVR1333D3N9/8G
HTS: 8473.30.1140, ECCN: EAR99
Specs: DDR3, 1333MHz, Non-ECC, CL9, 1.5V, Unbuffered, DIMM, 240-pin

thinking I had done my homework and had made the right choice, I completed the online order...

Then today when I was reviewing my MOBO specs I noticed something. It calls for the following kingston PN:

Kingston
8GB Module - DDR3 1333MHz
Part Number: KVR1333D3N9H/8G
HTS: 8473.30.1140, ECCN: EAR99
Specs: DDR3, 1333MHz, Non-ECC, CL9, 1.5V, Unbuffered, DIMM, 240-pin

Notice the letter "H" in the part number? Well I didn't  

So in a panic, I began to read. I read the spec sheets on the two directly off of kingstons site and compared every letter...every number and every conceivable piece of information in the two spec sheets start to finish. LITERALLY the only difference I found between the two documents is the inclusion of the letter "H" in the PN name and the document number and date of publication. All specs are identical as is physical dimensions of the two products down to the punctuation marks....

I'm thinking this is a typically "newbie"question but I'm stumped! Google searches led me no where and various tech sites have offered no insight. So my question is: What's the difference?