The Butterfly Kit provides an anterior chest support/ 4-point trunk harness. It attaches to the padded back of the School Chair with adjustable straps and is especially helpful for children with low muscle tone or decreased strength and endurance of core muscles which results in leaning forward or difficulty remaining upright with shoulders back and head up. The Butterfly Kit can be used as needed as part of a program to improve trunk control. The child can sit without the support controlling their own posture until they are unable. At that time, the chest support can be applied. By attempting to slowly increase the time the child can manage their own posture, strength and endurance of postural muscles is gradually improved.