This vest makes me very visible at night (my husband can attest to this when he could see me clearly at night driving a block and a half behind me. It’s a little smaller than you might expect, but since it’s not actual clothing, that’s fine. When on, it covers only my chest and upper back. The advantage is that it can be rolled up into a very small package and kept in your pocket or in a bike water bottle cage container with plenty of room for other things.
I also find it fairly usable for wrapping around my black backpack at night for nights when I’m riding with my bag.
Disclaimer: I received this item at a discount to share my unbiased opinion.