* The Ambu patented hygienic system protects the student and makes internal cleaning entirely unnecessary * Airways open only when the cpr manikin head is correctly hyperextended * Stomach inflation indicated by a whistling sound *Comes with 2 face pieces & 25 disposable head bags. ACD CPR-compatible (optional ACD CPR base board) * Dimensional Weight: 34 lbs *Shipping Dimensions: 32x11x19 *