You are purchasing a lot of 10 (ten) 20 position single row socket strips. They are manufactured part number 51AG90D-20. They have 1 row of 20 contacts spaced on .100 inch (2.54 mm) centers. These socket strips are "break-apart" design and can be either broken into smaller lengths or stacked in any way to make longer or side by side configurations while maintaining the .100 inch centers. The high reliability (these are the best specs available) machine contacts are heavy gold plated as are the thru-hole leads. These connectors are unused excess distributor inventory.