$13.99 – 100x70mm 90 Degree Angle Corner Square Ruler (Banggood, Aliexpress: Color: Silver, Material: Stainless Steel, Measurement Accuracy: DIN875-0 Grade, Size: 100x70mm (the best price with coupon)).
You can get 100x70mm 90 Degree Angle Corner Square Ruler for $13.99 using coupon code (in Banggood). Price history, coupons and price alert are available on this page. Best price?
Latest coupon and price update (UTC):
Banggood ($13.99)
Banggood warehouse is located in China. I couldn’t find any coupon for this product on latest product update. Is it a low price? Hmmm, price is higher than average (which is $11.99 right now), so better set price alert down below…
Link: Banggood product page
Price: $13.99
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/feV
Old coupons (from the oldest to the newest): BGherra, BGBFCR32, BGsqus18, BGsqus20, BGbackwo, BG18baofu, BGDRB18, BG17331, BGb77dcc, BGWT15, BGa0b557, BGc8412f, BGWDT15
(there’s a little possibility that old coupon will 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 100x70mm 90 Degree Angle Corner Square Ruler is here. The lowest price was: $8.99.
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)).