Someone asked where it shows where your disk are located rather the upper or lower bay. It shows this in the disk utility.
Name : OWC Mercury Extreme Pro SSD Media
Type : Disk
Partition Map Scheme : GUID Partition Table
Disk Identifier : disk0
Media Name : OWC Mercury Extreme Pro SSD Media
Media Type : Generic
Connection Bus : SATA
Connection ID : "Lower"
Device Tree : IODeviceTree:/PCI0@0/SATA@1F,2/PRT0@0/PMP@0
Bay : "Lower"
Writable : Yes
Ejectable : No
Location : Internal
Solid State Disk : Yes
Total Capacity : 240.06 GB (240,057,409,536 Bytes)
Disk Number : 0
Partition Number : 0
S.M.A.R.T. Status : Verified
Name : ST9750420AS Media
Type : Disk
Partition Map Scheme : GUID Partition Table
Disk Identifier : disk1
Media Name : ST9750420AS Media
Media Type : Generic
Connection Bus : SATA
Connection ID : "Upper"
Device Tree : IODeviceTree:/PCI0@0/SATA@1F,2/PRT1@1/PMP@0
Bay : "Upper"
Writable : Yes
Ejectable : No
Location : Internal
Total Capacity : 750.16 GB (750,156,374,016 Bytes)
Disk Number : 1
Partition Number : 0
S.M.A.R.T. Status : Verified
The stock drive comes installed in the lower bay, which I replaced with the SSD and of course this is my primary boot drive.