The Sipper Straw Insert converts the RoseCup to a feeding device with more volume control.
This insert enables the user to suck without hands with the cup standing on a table. The ball-valve mechanism provides easier sucking once the fluids reach the top of the sipper. As soon as the user stops sucking, the fluid will stay in the spout ready for the next suck.
The advantage above using a straw is that the user has to suck very hard to get the fluid to the top. As soon as sucking is stopped, the fluid will flow to the bottom of the cup.
The best part of the ball-valve mechanism is that this can happen without the hassle of continuous, strenuous sucking.