I purchased a 4L size for my golden retriever (about 36 kg). The suit was a bit tight but the material stretches well so I think either this size or a 5L would have been fine. It is very soft to the touch and seems very well made. It was easy to put on. My dog is not used to wearing items of clothing so he was not too happy but I am sure once he gets used to it, it should be fine. Overall, I am satisfied with the purchase and may consider buying another one if I notice a difference with hair shedding which is the reason for this purchase.