I purchased these freezing trays on Amazon. I used to use Richell, but I didn't notice any difference in how they work. These are slimmer and don't take up as much space in the freezer. They have been opened, but I haven't used them, and I'm selling them. I stored them in the cupboard in their original bags. There are two S size trays (15ml) and four M size trays (25ml).