This is a replacement pack of five Innokin iClear 16 dual coils. They have two long wicks, one for each coil within each replacement head which means that the juice is more able to flow consistently whatever position the device is in. It is well worth making sure that you have a supply of spare coils. This is because they do wear out and as they get older the flavor and the amount of vapor will reduce. They may need to be changed as often as every few weeks depending on how often you use them and the type of e-liquid that you use. This means that it is a good idea to have a spare supply of them ready for when you do need them so that you can change them when necessary. Otherwise you may find that your vaping experience is not as good as it could be.