Material: Stainless Steel, Voice value: 35 dBA, Power: 35W / 50W, Size: 175mm ×110mm×135mm, Color: Blue, Working hours: 3min~5min, Inner trough size: 152mm × 85mm×63mm, Ultrasonic frequencies: 43-45KHz, Capacity: 500 – 700mL, Model: BK-3550, Display: LED, Voltage: AC 220V.
Check coupons or create price alert down below. Let’s see what best price is ATM.
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.
Link: Banggood product page
1. ($74.69): BGHONEY2110
2. ($81.99): 13f142
put item in your cart and apply coupon code there 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): BG8ZYX, bGhOnEy10, BgoFErTaSchInA10, BGELIG0920, BgcLuBofErtA10, BGAFF10OFF, BGCuponation10
(there’s a little possibility that old coupon will work)
Price history and price alert
Price history (for all/most countries) for BK-3550 35W/50W 220V Ultrasonic Cleaner is here. The lowest price was: $52.88.
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)).