Various sizes of cork lids, perfect for terrariums. Choose one that fits your container like a glove - no more (or less) lid than you need! When picking the size, please pick the size for your terrarium opening. The actual sizes of the cork lids are as follows, with the middle size being the bottom, the large size being the top and the smallest size being the height of the cork. 20cm (205x195x30mm)Read more Sprouts of Bristol 20cm Terrarium Cork Lid Stopper Bung - Trouva