Thickness of bottom plate: 1.5mm, Co-Brand: Flywoo & Dave_c, Item Name: Explorer LR 4 Inch Frame Kit, Thickness of top plate: 1.5mm, Material: 100% 3K carbon fiber + 7075 aluminium alloy, Weight: 41g, Thickness of arms: 3mm.
Just check coupons out (with price alert and history). Best price?
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 coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
1. ($39.99): BG42c462
2. ($50.59): BG1efeb0
apply it in your cart after clicking “Proceed to checkout”. Click to copy code and open shop.
Additional Banggood coupons: first page and second page
There were country-specific coupon codes published on Couponsfromchina social channels and price alerts. Coupon price may vary by country, because there’re different VAT rates, shipping cost etc. There is a chance that some latest coupons are still working:
Old coupons (from the oldest to the newest): BG1ef0b8
(these coupons are old, so probably won’t work)
Price history and price alert
Here is price history (for all/most countries) for Flywoo Explorer LR 4inch Frame Kit V2 Analog. The lowest price was: $39.99.
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)).