Quantity: 1bag=10pieces, Model: 191-212.
Basically copy coupon, view price history or create e-mail price alert. Do you want to know what the best price is?
Aliexpress
I could not find it on Aliexpress. 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. I couldn’t find any coupon for this product on latest product update.
Link: Banggood product page
Price: $-3
It looks like this item is out of stock in Banggood. If you found it then please send me the link. I will replace it.
Click here to search on Banggood!
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/i1u
Old coupons (from the oldest to the newest): AFfbG10, 502C6B, BGBFAFF2019, BGCITYADS2019, BGMPB2020, BGAFF10OFF, bGhOnEy10, BGherra, BGTool15, BGRUS15, BGWELDTOOL, BG8a7644, BG00c906, BGGines, CityadsTool
(I don’t think these’re gonna work, but you can try ’em out anyway)
Price history and price alert
Here is price history (for all/most countries) for Lead Free Sensor 191-212 for Tip Thermometer Soldering Iron. The lowest price was: $3.6.
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)).