nd:yag wavelength is effective for reaching the deepest layers of the skin, while the er:yag wavelength is ideal for brushing away surface imperfections to reveal visually attractive nd:yag laser technology provides the power and performance needed to handle a wide range of aesthetic applications, from skin rejuvenation and acne and much more more than 300,000 s, the handle lasts longer, treats more clients, and brings you more money. if you have any questions after receiving the goods, please contact the seller as soon as possible.we will serve you wholeheartedly, but we will not accept disputes presented in bad faith.once shipped, we will automatically give up after-sales service by default..syi