SAVE 50%: As of Oct. 9, you can grab the iRobot Roomba j7+ at Walmart and Amazon for just $399. That's $400.99 off its $799.99 MSRP.

Opens in a new window Credit: iRobot iRobot Roomba j7+ $399 at Walmart and Amazon (save $400.99) Get Deal

Walmart's anti-Prime Day sale has started, and they've wasted absolutely no time unveiling some highly competitive deals.

One huge example — on the first day of their sale on Oct. 9, Walmart came out kicking with an iRobot Roomba j7+ on sale for just $399. That's $400.99 off its $799.99 MSRP. Although Prime Day doesn't officially kick off until tomorrow, Amazon was not to be outdone, so they've also slashed the price of the j7+ to $399. This marks the robot vacuum's lowest price ever by far.

SEE ALSO: Everything you need to know about Amazon Prime Big Deal Days: 100+ early deals, dates, invite-only deals, and the competition

Just over 50% off is noteworthy on its own, but when you take into account that days ago, the Roomba j6+ — the slightly cheaper model with less accurate object detection — was down to its lowest price ever the same exact price of $399. Now, you'll get the same 60-day self-emptying, 90 minutes of battery life, and great suction power, all with the addition of PrecisionVision Navigation, which gives this vac top-tier object detection.

In fact, the j7+ is our favorite robot vacuum for avoiding small obstacles — so if you like not having to think about every single wire/pet toy/sock that might be out on your floor before your robot vacuum does its thing, this is the pick for you.