Fit is individual
Chest shape, coat, movement and the dog's normal activity affect whether a harness sits comfortably.
Attachment points differ
Front and back attachment layouts change handling feel but are not a substitute for training.
Check adjustability
Multiple adjustment points can help when body proportions do not match a simple size label.
Inspect wear
Frayed webbing, cracked buckles or damaged stitching should not be treated as cosmetic defects.
General product-selection information only. A pet's health, anatomy, mobility, breathing and behaviour can change what equipment is appropriate. Follow product directions and ask a veterinarian or qualified animal-care professional when those issues matter.