Homebrew 13 Dbi Omni 2.4Ghz Antenna

This omni antenna is strange , I can not get the idea here.

13dbi Omni WIFI Antenna - this must be an Do It Yourself version of HACKED original omnidirectional wifi antenna.

Look interesting but I do not promise anything here.

Materials needed for this DIY antenna :

PVC tube 20 mm,

PVC tube with copper tube inside of it and inner diameter 15mm,

2.5mm copper wire

Here are the pictures :

There are two spinals here - one is clear - but I cant get were is connected second one.

UPDATE - there is metal ring in the center of this antenna ! Here second line is connected.

13dbi diy omni wifi antenna coax