Another perennial favorite on Prime Day is the Instant Pot, Wirecutter’s pick for the best electric pressure cooker, and the subject of a wonderful guide from NYT Cooking. In the summer of 2016, the Instant Pot was a cult favorite with a growing following. Interest ticked up in July 2016, when it was the top-selling non-Amazon device in the US on Prime Day, selling 215,000 units, according to Amazon. The following Prime Day in 2017, the Instant Pot again topped the best-seller list in the US, excluding non-Amazon devices. And on last year’s Prime Day, Amazon sold 300,000 Instant Pots. (The company behind the Instant Pot declined to speak to us about this article.) We wouldn’t be surprised to see a deal on one of the newer models for the fourth year in a row.

The LifeStraw, a straw-style water filter marketed for outdoor recreation and emergency preparedness, also topped best seller lists with a deeply discounted price of $10, down from about $16. After selling more than 150,000 units, the company had to pull the deal down before the end of Prime Day because it sold out all of the inventory it had available.

“We had originally forecast what we thought was a very aggressive target of 100,000 units for this promotion, and by noon or 1 p.m. of Prime Day, we quickly realized that we were going to blow that out of the water,” said Emily Myer, LifeStraw’s head of eCommerce.

LifeStraw proved surprisingly popular as an impulse buy for people who didn’t even participate in outdoor recreation. “We had fantastic traction with those customers who view our products not necessarily as a product that they need because they’re going camping next weekend, but for the price point that we could offer on Prime Day, customers were buying this for their emergency kits, for a bag that they have ready to go for an earthquake or another kind of natural disaster or emergency event,” Ms. Myer said. Although companies aren’t allowed to say whether they’ll participate in Prime Day this year, the LifeStraw is featured as a best seller from last year on Amazon’s Prime Day Guide page, and Ms. Myer said, “I will say we are very excited about what Prime Day has in store this year.”

Wirecutter best sellers on Prime Day

Each year on Prime Day, the Wirecutter Deals team sifts through thousands of Prime Day deals and highlights only the best discounts on the things that we think are worth buying. Each year the number of deals we’ve been able to share has grown. Here are our readers’ five most popular Prime Day best sellers for the past four years.