I use a prong choker chain. Coco (lab mix) was a HUGH puller, not now he walks slightly ahead of me or beside me and we both love walking. He pulled every muscle in this body before I went to this type of collar. I barely have to tug on the leash and he immediately stops pulling if he gets walking little faster than me. They (collar) looks horrible but they dont hurt the dog.

Harness never worked for large breed dog like Coco.