The SDL 'EC' line has a special optic which is designed to be in contact with the skin. This allows for far greater absorption and penetration of the laser energy to the desired tissues. With surface laser epilation (the standard SDL line) a significant percentage of the laser energy simply bounces off the skin or is absorbed by the hair itself. This creates quite an impressive effect as the laser 'shaves' the skin, however, of 150jcm2/second energy delivered this way, only about 100jcm2 will pass through the skin. This is why the SDL 'EC' line was developed. This method of laser application has a 97% efficiency at penetrating the dermal barrier. It is intended to be performed in conjunction with a topical gel paste (which also contains lidocaine for additional patient comfort). As the SDL-EC glides across the gel-coated skin it delivers high fluence pulses deep into the desired tissues. The results are faster and more substantial than the standard SDL line of surface epilators.