Upgrading a server for the first time in 10 years, so I’m a little out of the loop. I was surprised to find that the RAM I bought didn’t fit.

This is my first time dabbling in ECC RAM, so I figured there was some minor detail I missed when purchasing, but I eventually came across the data sheet for this stick, and the dimensions given don’t match the measurements I’m making.

What’s more is that the dimensions in the data sheet seem to match the dimensions on my motherboard. What’s going on here?