Personal moulded earplugs are the best type available. There are several advantages to this type.
One. They are individually made for your ears so are incredibly comfortable and make a perfect seal with your ears. This makes them great at keeping sound and water out.
Two. ZenPlugs personal moulded earplugs are especially designed not to protrude from your ears so are comfortable even when lying on your side in bed. This is unlike many other types of earplugs which stand proud and so push the plug into your ear canal when you lie on your side. Also, on rolling over the plugs can be knocked out of your ears. You are woken up by the discomfort and the noise that you are exposed to.
Three. Personal moulded earplugs are much longer lasting than other types. The initial costs may be higher but the cost per use is much lower because they last for many more uses than other types. Foam, wax and soft silicone earplugs often need to be replaced after only a few uses because they become dirty, discoloured and break.
Four. This type of earplug can be connected on a cord. Many others cannot. This makes them ideal for swimming and other sports. Wax and soft silicon earplugs are often used for watersports but they tend to fall apart and bits get left in the ears. They may need to be removed by a doctor. Additionally they cannot be connected on a cord. This means that if they come out of your ears then you may lose them. The cord on ZenPlugs also makes it easier for you to keep them together and find them in your kitbag.
Summary. ZenPlugs are the best personal moulded earplugs available. They don't protruding from the ears, making them comfortable for sleeping.