I used to buy mine at Western Auto. As I remember. the ones I got were the size that the large patch in modern patch kits (these were the small ones for bikes). I used them on my tube (had a Schwinn Wasp) and never had a problem. I tried to find them a month or so ago without any luck. I think when cars went to tubeless tires, the demand was not worth the production cost. I remember them as being the 100% sure way to patch a tube.