Soft is strong, comfortable and now, flawless. Get the innovative soft gel nail extension system, Salon X-tend by KISS. This revolutionary gel nail extension kit is easy to apply, and includes everything you need to create a stunning salon quality manicure in minutes. What are gel nail extensions? The Salon X-tend soft gel nail extensions kit features soft gel nails that are applied to your natural nail using a gel and led lamp for a clean and easy application that lasts up to 14 days.