Complex sentence: The most noticeable difference between a bullwhip and an Australian stockwhip is that the handle of a stockwhip is not integrated into the thong, instead it is attached to the thong by a keeper, to stop the thong from slipping off.
Split into simpler sentences: The most noticeable difference between a bullwhip and an Australian stockwhip is that the handle of a stockwhip is not integrated into the thong. Instead the handle is attached to the thong by a keeper, to stop the thong from slipping off.