"This lasts for hours."
Translation:Ça dure pendant des heures.
"ceci/cela/ça" = this/that, as a pronoun that can be subject of a verb; here: ceci/cela dure = this/that lasts.
"ce" as a pronoun is only used with verb être: c'est, ce sont.
"dur" is an adjective (dur, dure, durs, dures), meaning tough/hard.
Verb "durer" (= to last) is a 1st group verb, like "manger": je dure, tu dures, il/elle/on dure, nous durons, vous durez, ils/elles durent.
What "ça/this" represents is not known (a concert, a fight, a game...).
The most correct translation should be: "ceci dure (pendant) des heures"
I was confused about ceci/cela. If anybody else is here's a good explanation: http://french.about.com/od/grammar/a/indefinite-demonstrative-pronoun.htm