Fit and sizing guide
Measure his chest, not his breed. Ten seconds with a tape decides the whole thing.
How to measure him, in 10 seconds
- Stand him up. Find the spot just behind his front legs, where his ribcage is at its widest.
- Run a soft tape or a piece of string all the way around: over the back, under the chest, back to where you started.
- Snug, not tight. You want two fingers to slide flat underneath.
- If you used string, lay it against a tape measure. That number is his chest girth.
Match the chest girth to the chart. Weight is a sanity check, not the answer, and breed is not an answer at all. Two 50 lb dogs can be four inches apart in the chest.
The size chart
| Size | Chest girth | Neck girth | Weight guide |
|---|---|---|---|
| S | 19.3 to 25.2 in (49 to 64 cm) | 11.0 to 16.9 in (28 to 43 cm) | about 8 to 15 lb |
| M | 21.7 to 28.0 in (55 to 71 cm) | 11.8 to 20.1 in (30 to 51 cm) | about 15 to 35 lb |
| L | 26.0 to 35.0 in (66 to 89 cm) | 13.4 to 23.2 in (34 to 59 cm) | about 35 to 66 lb |
| XL | 30.7 to 39.8 in (78 to 101 cm) | 19.7 to 31.9 in (50 to 81 cm) | about 66 to 110 lb |
Chest girth first, inches first. This chart is published exactly as our supplier prints it, converted to inches at 2.54 cm per inch. We have not averaged it with anyone else's.
Between two sizes
Size up. Every strap on this harness takes in at four points, so a size that starts a little roomy can be tightened down. A size that arrives a little tight cannot be let out. A public review on the near-identical model reports the largest size running small on an English Labrador, which is the direction of error we would rather protect you from.
Setting the four straps
Do this indoors, with nothing clipped to him, while he is standing still and bored. Not on the doorstep while he is vibrating.
- Open both side-release buckles, at the neck and at the chest, and lower the harness onto him rather than pushing it down over his face. It is an over-the-head vest, not a step-in, and opening the neck side is what makes that easy.
- Buckle up, then set the neck strap. Two fingers should slide flat underneath.
- Set the chest strap the same way: two fingers flat, no more.
- Look under his front legs. You want webbing sitting clear of the armpit, not pressed into it. Move the sliders until it does.
- Walk him around the kitchen for a minute and check it again. Webbing settles.
Check the fit every few weeks, and after a wash. A chest strap that has worked itself loose changes where the pull lands, which is the thing you paid for.
Which ring to clip to
- The ring on the chest plate is the one that does the work. A pull turns him off his line and back toward you. Use it anywhere busy, and for the first two weeks everywhere.
- The ring on the back is for the easy stretches, when nothing needs redirecting.
- Both at once if you own a double-ended lead. That is what a lot of trainers do.
The front ring changes where the leash pressure lands. It does not change what your dog wants, and it is not training. It gives you a walk you can hold with one hand, which is the thing that makes training possible.
Growing puppies
A puppy's chest can change a great deal in a few months, so you may be buying a second one later in the year. That is a growing dog, not a defect. If he is near the top of a size range and still growing, take the bigger size and run the straps in.
If it arrives and the size is wrong
Sizing is the number one reason harnesses come back, in this category and on this page. So measure once before you order. And if it still comes out wrong, message us with his chest measurement and the right size ships free. You keep the first one. There is nothing to ship back.
No photos, no window to beat, and a size exchange does not use up your 90-day guarantee. Full terms on our returns and guarantee page.
Safety and limits
- This harness is made for daily walking. The maker specifies it for daily, light walking and tells owners to avoid extreme pulling and sudden forceful tugs.
- It is not a tie-out and not an anchor for a stake, a zipline or a trolley run.
- It is not a vehicle restraint.
- We publish no breaking strain, because nobody has tested one of these to a standard we could honestly cite.
- Do not leave it on an unsupervised dog, and check the stitching and the buckles from time to time.
- If pulling comes with lunging, growling or a bite history, that needs a qualified trainer and a second point of contact, not a harness and some hope.
Washing it
Hand wash in cool water with a mild soap, rinse it thoroughly and air dry it out of direct sun. No tumble dryer, no bleach, no iron. For everyday mud a damp cloth does the job. We give you the cautious instruction on purpose: the maker does not publish a machine-wash rating for this harness, so we are not going to invent one.