You'd definitely be pushing the camera's sensor with those!
But when I looked at the price, my eyes almost fell out of their sockets!
If you want a luxurious pinhole for your reflex camera, take a look at these
http://skinkpinhole.com/wp/They've been on my ebay watch list for a few years now. I can't decide to get one considering they are a bit over 100$, but I must say they look really nice.