The SONOtrain Gallbladder model is an ultrasound block that has three gallbladders with different pathologies: Gallstones (diameter: 8 and 10 mm), thickened gallbladder wall and biliary sludge deposit.? The gallstones and the sludge in the gallbladder model can move around and react to changes in position. The material of the SONOtrain trainer simulates the feel of real soft tissue for carrying out palpations and injections and shows realistic texture and echogenicity on ultrasound images. The SONOtrain trainer is easy to use as a teaching tool for basic training and for improving dexterity and hand-eye coordination skills.