998e2bac_n_of_No_Pull_Dog_Training_Aids__2
[0] Limited Slip Collar or Limited Choke Collar or Martingale Collar [1] Premier Collar [3] Dog doesn't generally mind having it put on. Prevents escape due to backing out of the collar when properly fitted. Does not choke when properly fitted. [4] Not very effective at reducing pulling in most dogs and puts a lot of pressure on the trachea if the dog pulls. Can be a good regular walking collar for dogs that do not pull or as a back up for a harness. [5] 3 out of 10 (for reducing pulling; it is a good collar for other purposes.) [2] 
When the dog pulls, a cord or chain tightens around the dog's neck which is unpleasant and discourages him from pulling. (When fitted properly the collar will not tighten down enough to choke.)