The sentence that contains filler is: "Your kids will love the LEGO Star Wars Republic Fighter Tank and spend hours building it to completion."
In this sentence, the phrase "and spend hours building it to completion" is the filler. The sentence could be simplified to "Your kids will love the LEGO Star Wars Republic Fighter Tank." The additional information about spending hours building it to completion is not necessary and can be considered filler.
Fillers are extra words or phrases that are not essential to the meaning of a sentence. They can often be removed without changing the overall message. In this case, the filler is adding extra information about how long it might take to build the LEGO set, but it is not necessary to understand the main point of the sentence, which is that kids will love the toy.
By identifying and removing fillers, we can make our writing more concise and focused on the main idea.