i think it's a cheapy and you get what you pay for...no offense meant.
i also think you should be aware that if you put a 2x or 3x multiplier on a 12x zoom camera and want to get anything decent out of it, you should plan on shooting pics off of a tripod. you won't be able to hold it still enough and you will also need a whole lot more light. why do you want one of these? what is your goal in the end?