The one thing I noticed about the 405 vs the 404 is that the hoses they sell with the 405 are really cheap plastic. I had a 404 years ago and remembered that 404 hoses were silicone and difficult to break or kink (like the Rena xP3 hoses I have now). I had a 404, loved it, got a 405 new, saw how cheap the hoses looked, then returned it and got a Rena.