Need advice on Blood Tracking Lights

[Canadian Black Bears]

Has anyone tried a blood tracking light like this one...http://www.sportsmansguide.com/net/c...aspx?a=421674?

I bought one for bear season last year but didn't have to use it as my guests shot their bear with a bow early evening and we didn't have to chase it. I am not sure if it was a good investment or not? I do use peroxide when following a blood trail as it works perfect. It foams as soon as it hits blood and makes it easy to follow a blood trail.