When it comes to keeping your pants from falling down while running from Daleks, you can go belt or suspenders. Or as the Brits call them, braces. What we have here are purple suspenders that are patterned to match the ones worn by the 11th Doctor in a few episodes.
That would be the Doc played by Matt Smith. If you are wondering, the go perfectly with the 11th doctor’s bow tie, so you can be ready in sensible clothes for a night out.
I always thought you wore either suspenders or a belt, not both like the guy in the image here. Get your pair of 11th Doctor suspenders at ThinkGeek for $39.99(USD). You can also get them in red if you prefer that look.