Genuine SmokTech brand of XL Dual Coil Low Resistance Cartomiser features a radical new design which boasts increased coil surface area for maximum vapor production. This design allows heat to be transferred to a larger surface area than previous low resistance cartomisers, which force heat to a concentrated point with minimal surface area. For the user, that means shorter draws and increased vapor production, an advantage not previously available in low resistance cartomizers. These are longer then standard 510 cartomisers and hold approximately 1.6mL of liquid. These are rated 1.5 ohm.