In the initial days of enteral feedings, the choice of pumps for delivering formula to patients was limited. Early devices were heavy, sat stationary at the bedside and used a rotary, peristaltic mechanism. When enteral feedings became more prevalent in the 1970s and '80s, pump manufacturers met the demands of a developing medical therapy with more sophisticated and practical features. At that time, smaller companies, along with the larger manufacturers of nutritional products, jumped on the wagon and a wide variety of pumps were made available. Currently, the market has narrowed to major companies who still provide not only the nutritional product but also the pumps to deliver them, and a few companies who manufacture pumps and devices only. Further, as the sophistication of the pumps increased, improvements were made in the design of the bags, delivery sets, and feeding catheters. Each manufacturer has a line of "accessories" to complement their pump and the variety available can provide the user with specific features to meet their needs.