Mix crushed pretzels,sugar and butter. Press into 9" pie plate. refrigerate until filling is ready.
combine condensed milk, lime juice, and kool-aid in a large bowl blending well.
Gently stir in whipped topping and pour into crust. freeze 6 hours or overnight. Let stand at room temp, for 15 min. before serving. store in freezer.. garnish with whipped topping to serve if desired! Enjoy!