I have used Kilner jars for preserving foodstuffs for years and have them in all different sizes. They are extremely durable. I prefer to wash mine by hand in warm soapy water after use. However if you do choose to put them in the dishwasher I would recommend removing the rubber seal first.
A thoroughly good product.
I was a little concerned about getting them so the first time I bought only one just to check when I realised the quality was amazing I made another purchase with two more I personally recommend 100%