What are the contact points for?

[GW1985]

I've just bought a G3 and have bought a case for it.
It's one of those cases that attaches to the back of the handset, which I hadn't realised. I have noticed that the back that comes with the handset has 4 contact points, but my new case does not.
Can anyone tell me what they do and what difference it will make that the new case doesn't have them?

 

[ypsmav]

These are for the wireless charger. If you have changed the back cover this function won't work.
Regards

Sent from my phone

 

[bean72]

It's also for the NFC antenna. You can purchase NFC/wireless charging stickers that are specific to your phone to stick on the new phone case if you require those features. I had to buy a sticker on amazon to allow me to use NFC with my zerolemon case