The Silk'n SensEpil disposable cartridge has the largest treatment size on the market, the spot size is 6 cm². Each cartridge comes with 1,500 pulses which is enough to do a lifetime of treatments small areas, such as underarms or bikini line. The applicator has a built in skin sensor to detect individual skin tones, taking out the guesswork during treatment. If skin tones are darker than allowable settings, the applicator will not flash, thereby providing you a safe home hair removal experience. *Results may vary based on hair or skin type. This Cartridge is compatible with the following devices: SensEpil 1.5k SensEpil 65k BellaLite 1.5k BellaLite Pro 20k *Device sold separately.