Set pretzels out on 2 ungreased cookie sheets in a single layer. You can add more pretzels if neccessary to fill up the cookie sheets.
Place caramel bits and milk in a Pyrex measuring container or glass bowl. Microwave for 1 minute. Stir with a spoon. It will not look like it is going to blend, but keep stirring and it will become smooth. If necessary, microwave for another 15-20 seconds and stir again until smooth. Drizzle over pretzels.
Place chocolate chips in a Pyrex measuring container or glass bowl. Cut 4 Tbsp. butter into 1/2 inch squares and place on top of chocolate chips. Microwave for 1 minute. Stir until smooth. If chocolate is not dipping consistency, melt 1 Tbsp. butter and while still hot, add slowly and stir until desired consistency. Drizzle over pretzels.
Refrigerate for 20-30 minutes to set caramel and chocolate.
Remove pretzels to a serving bowl or dish and enjoy!