I dpn't know the specific answer to your question but my m.2 slot looks like yours and I'm using an nvme ssd and it's running on pcie lanes.

antonunabia wrote:
My laptop, GL552JX, specification is 128GB 256GB SATA 2280 SSD.

Hi there, by the specification of your laptop it seems that comes with: 128 GB or 256 GB for the SATA connector storage (don't know if it comes with an SSD or HDD), then it has available a 2280 SSD slot. In other word an SSD compatible for the M.2 slot whose dimension is 2280 (22 mm x 80 mm). It says SSD because basically all the hard disk that fits an M.2 slot are SSD and the SSD can be further advanced by being SSD NVME.

M.2 slots can fit different types of SSD: 2242, 2260, 2280, 22110 all of them are in this form (height (forst two digits) x base (rest of the digits) of your SSD M.2).

I hope I was clear.

antonunabia wrote:
Can somebody tell me what slot is this ?
I believe it is a M.2 slot but got no idea if it is a PCIe or SATA III. My laptop, GL552JX, specification is 128GB 256GB SATA 2280 SSD.
Please enlighten me on this one. Follow up questions will follow upon your reply.

Thank you.

It appears to be a mSATA (mini SATA) connector, not M.2.

here you have an m.2 ssd.
its a normal ssd, but not in a cover like the other ssd's for example samung 850 ssd's out there ( 2.5" size ).
the numbers 2280 means = 22mm is the with for the drive ( witch is standard ) and 80 is the length witch will warry depending on size of the lenght that fit in the socket screws mounted on the mobo.
as you can see on your pc's mobo there is only one screw you can fasten it too, witch mean you can only use a 2280 m.2 ssd.

but as you can see on this mobo you can use diffrenth lenghts , as you can see on the mountings under the blue outlined surface witch simulates a 2280 m.2 ssd.