The term "GROSS CHT" doesn't exist in English vocabulary, so we cannot search for any antonyms to this non-existent term. It's possible the intended word was "Gross Weight," which would have several antonyms, including "Net Weight," "Tare Weight," or "Light Weight." Gross weight refers to the total weight of an object, including any added packaging or materials. Net weight, on the other hand, refers to the weight of the object alone, without any additional items. Tare weight is the weight of the packaging or container itself, and light-weight, obviously, is the opposite of heavy-weight, meaning that it has less weight.