Features： 1、WHAT IT DOES: The abdominal breathing trainer is a breakthrough breathing and abdominal fitness training product that will slim down your waist and abdomen. 2、CREATING PULMONARY RESISTANCE: This trainer is meant for diaphragmatic training to help you fully utilize and tone abdominal muscles while breathing. 3、FAT BURNING: This trainer can help you burn your fat, it trains you to breathe using your core muscles, which helps with fat burning and flattening your abdominals. 4、TIGHTEN YOUR ABDOMEN: The rebreather not only allows you to burn fat, it also tightens and tones your abdomen and trains the deep abdominal muscles, obliques and transversus abdominis. 5、BOOSTS METABOLISM: It adds energy to your lungs, boosts your metabolism, greatly reduces your appetite and has three adjustable training levels. Specification： Item Type: Breathing trainer Material: ABS Product Size: Approx. 10.5 x 4.5cm / 4.1 x 1.8in (error with ± 1cm manual measurement) Uses: Breathing training Package List： 1 x Breathing Trainer