Ideally, it's best to use the lamp that goes with that system, but Gelish only has LED lamps now and they say that a 36watt CFL UV lamp will cure Gelish. The CND CFL UV lamp is a really good lamp. It is 36 watts (4 bulbs) It is designed so that it encourages proper hand placement, the bulb placement and reflectors make sure that the light coverage is excellent, the pre-programmed timers are great, it keeps track of usage so you know how much time you have on your bulbs, love the cute handle which makes it easy to carry, removable tray makes pedis easy... Have I left out anything?
A good lamp is the heart of your gel polish system. A bad lamp leads to uncertain cures, service breakdown and unnecessary exposure to uncured gel. I know too many people who used the cheap lamps only to get allergies from exposure to uncured gel and it has made me really cautious about what lamps I use. To my mind, a CND lamp is one less thing to worry about.