There are a few disadvantages to being a black dog - the sun is hotter, as your coat soaks up the rays, and you blend into the night so people could easily walk into you.
The collar and the silicone lights use little 'coin' style batteries so I'm not sure how long they will last - so far I have only used the collar for our half hour walk, but hopefully we won't burn through them too quickly!
I made a little video on our walk tonight so you can see what it looks like when I'm walking about a metre behind her, letting her go to the end of her leash.
I wish they made these kinds of things back when I was into nightclubs and dance parties - they would be a hit!