CLA-XTRA appears to be (based on rough translation...all the sites are in Spanish) congugated linoleic acids (CLA) combined with green tea extracts.
CLA and Weight Loss - basically, the is an unknown. Two studies have shown that taking CLAs for 6 months may have some net effect on weight loss. The effect shown, though, was really small in both studies (about 3 lbs over 6 months). A different study showed no difference between CLA supplements and a placebo. Researchers are optimistic about CLA as a weight loss supplement, but a lot more research is needed before it can be recommended. In addition, the study participants in one study taking the CLA had some negative changes in terms of cardiovascular health, including higher cholesterol and blood sugar values.
The other ingredient appears to be Green Tea Extract. This is another ingredient that has shown some promise in terms of weight loss, but needs further study and has, in general, shown only modest results.
So there are some promising ingredients there, in that they have been shown to have a very small benefit in studies. That being said, though, there is ALWAYS a question with any supplement of quality/bioavailability/ concentration/dosage of ingredients. Even if 600 mg of green tea extract was shown to increase weight loss in a study, a pill with 50 mg probably won't have the same effect.
Definitely more research is in order.