Are sharp, but the blade slips from knife handle out

The knives are super sharp and cut everything like butter, but after some time slips the blade when cutting from the knife handle (grip), the blade can, however, back into the knife handle insert. But if you have to cut so much that can go right on a nerve that slips the blade again and again on the knife handle. The peeler is not the sharpest degree, peel the carrots it has totally failed! The value for money is OK, but a bit expensive, but the one after about 10 times using the blade must always stuck in the knife handle. I would only buy the knife to me again when the blade actually the knife handle is tight and does not slip out of use after about 10 times.