As of July 3, the iRobot Roomba Plus 405 is on sale for $399.99. This deal saves you $400 on list price, and is the lowest-ever price according to camelcamelcamel. Our robot vacuum expert has hand-picked this deal as one of the best ahead of Prime Day.

Amazon Prime Day typically brings great discounts on all sorts of electronics, but it’s a good idea to go for the expensive gear first. We consider robot vacuums to be in that category because, while there are solid affordable models available today,

Don’t stress anymore when you get home about having to mop and vacuum. You should enjoy a clean home when you get back from a long day of work, a nd the iRobot Roomba combination mop and vacuum can make that happen for just $400—a 50% discount for Amazon Prime members.