iPhone 4 4s screen replacement repair kit is use to repair your broken glass on your iphone. if you accidently droped your phone and cracked your outer screen but your LCD screen is working then this is the kit you will need for the repair. your lcd screen is the one that shows the picture on your phone when you turn it on. most of the time when you drop the phone the front glass outer screen is what gets damged. this kit includes the adhesive double sided tape thats use to apply on the new glass so it can hold together with the lcd screen. or we also include the loca glue wich is another way to apply the new glass on the lcd . after you apply the loca glue you will use the UV light to dry the loca glue. you will find everything you need for the job at our website.