Hold the older model. The strips are for no-go areas. It has a drop sensor for stairs, mine has never fallen down the stairs. I definitely won't contact it a rubbish vac as mine is really very good (Here is the product with Alexa which was on sale at Amazon http://edwinfvhsz.digiblogbox.com/19930980/a-simple-key-for-shark-vacuum-cleaners-boulder-unveiled