Since 1886, Stoelting Co. has been a leader in manufacturing superior instruments and assessments for basic scientific research and practice. We are proud of our tradition of manufacturing and supplying superb products…and remain committed to our customers' needs through knowledgeable and prompt customer service.The Psychological Tests Division is currently researching and authoring innovative new testing materials, and our Leiter-R Performance Scale and Merrill-Palmer Scale are two of the most recognized tests in the world.