The Geek Vape Aegis Boost Replacement coils are designed for the Aegis Boost Pod System. Each one securely fits within the devices pod and features a friction fit o-ring system. Each of the coil options are designed with flavor in mind both utilizing a mesh coil which adds not only in flavor depth but coil life as well. One of which is the 0.4 ohm Kanthal Mesh coil which is best used at 25 to 35W. The other variation is the 0.6 ohm Kanthal Mesh coil which is designed to be vaped at 15 to 25W.