A system includes a first container having a wall defining a receptacle, a neck defining an opening, and a flip cap disposed over the opening, and a second container having a wall defining a receptacle, a neck defining an opening, and a flip cap disposed over the opening. The system also includes a carrier having first and second carrier pieces disposed about the first and second containers and attached together with the first and second containers secured therebetween. The system further includes a top cap attached to the flip caps to secure the first and second containers together and to simultaneously remove the flip caps from the containers.