Cross-Polar Rejection: -10 to -28dB (2.4%), Cable: Flexible RG178, Item Name: Micro AXII MMCX, SWR: <=1.5: 1, Gain: 1.6dbic, Cable Length: 60mm, Bandwidth: 5.5GHz-6.0GHz, Radiation Efficiency: 98%, Weight: 2.2g, Polarization(optional): Right Hand Circular (RHCP), Compatible with other styles of 5.8GHz RHCP/LHCP antennas, Left Hand Circular (LHCP), Size: 12mmx 9mm, Connector: MMCX. Price history, coupons and price alert are available on this page. Let’s see what best price is ATM.
Aliexpress
There’re some similar (or not) items on Aliexpress
You can use link bot to get even lower price:
Click here to search by yourself. Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
1. ($17.99): BGTT10
2. ($18.59): BGAFF7OFF
3. ($18.99): 13f142
apply code in your basket (cart) after clicking “Proceed to checkout”. Click to copy code and open shop.
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): BGBCBG10, aff7off, bgchinafest, BGOTC21, BGBFAFF2019, BGCITYADS2019, bGhOnEy10, BGSS10%SW, bgshOOp10, BGHALLOWEEN
(these coupons are old, so probably won’t work)
Price history and price alert
Do you need price history chart (for all/most countries) for Lumenier Micro AXII MMCX 5.8GHz 1.6dBi FPV Antenna? There we go. The lowest price was: $16.99.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood and Aliexpress (only if product name will be the same as on Banggood and I will post it on social media though, so it’s more like Banggood price alert)).