$6.29 – Material: PC, Number of blades: 4-blade, Paddle disk diameter: 40.8mm, Weight / G: 0.61G, Maximum blade width: 7.46mm, Adaptation motor: 1103-1105 Recommended motor: 1103, Center hole inner diameter: 1.5MM, Pitch: 3.5in, Center thickness: 5.2mm.
ATM you can buy 4 Pairs Gemfan 1636 1.6×3.6×4 40mm 1.5mm Propeller for $6.29 (in Banggood). Go down and check coupons out. Remember to check price history if it is available. You probably want to know what is the best price?
Latest coupon and price update (UTC):
Banggood ($6.29)
Banggood warehouse is located in China. I have no active coupons for you right now. Well, is it a good price anyway? Hmmm, price is higher than average (which is $4.77 right now), so better set price alert down below…
Link: Banggood product page
Price: $6.29
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): 10Gemfan, bgssaff9, AFfbG10, BG12MRP, BGGEPPart, BGVDay10%off, Parts8, BGAFF10OFF, BGTT10, bGhOnEy10, BGdragonBoat, BGSS10%SW, BGRC902, BgoFErTaSchInA10, BgcLuBofErtA10, BGDAVIS, BGHONEY2110, 13f142, BGGAL8, BGJON8, BGRCParts8, Tabby20, BG1efeb0, 8Couponsde, MVC8SPRING, 8BGwbg2204, tRaDetRaCKeR, 8wEbgaInS5, pROMo8cuPoN, BG8RCToy, BGRCT10, BGJUNEGSG9, TTSUMMER8, Cuponation9, BGMatt2022, BGToys8, BG589b2e
(these coupons are old, so probably won’t work)
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.
Price history and price alert
Price history (for all/most countries) for 4 Pairs Gemfan 1636 1.6×3.6×4 40mm 1.5mm Propeller is here. The lowest price was: $4.58.
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)).