Fifty {Two} Shades of Grey - Week 11

I really hope this one is a bit more difficult to pick what it is.

I really like the look of the stripes which are not part of the item itself but purely a result of it reflecting the things around it, even though it doesn't have a particularly reflective surface. I'd describe it as having more of a brushed metal surface so it would be expected to distort anything it did reflect.
This is my metal water bottle. I use it daily. It travels everywhere with me... out on trips, to work, down in the studio, beside my bed... it follows me like my shadow.