next time please use the search function. many members, including myself, have answered this question many times. ill give you a free pass and answer it anyways.
will it get through customs? lazerer does a good job of packaging their lasers and getting them through customs. i have one that got through and many members are in the same boat. now if you throw batteries into the equation i would say less than 50% chance. it is super easy to find a li-ion battery on a scanner and customs is strict on batteries so they will most likely open your package and boom, laser inside as well. now you have given them everything needed to test your laser since the batteries are right there. if they do open your package due to the batteries id say 100% chance you wont get it.
long story short, order the laser and JUST the laser. buy the batteries from w/in the US