This is a 24 pin IC Narrow Base (DIP Socket) with pins spaced at 0.1"(2.54 mm) .Use this IC base for easily plugging in and out ICs during prototyping. Also use this IC base to protect IC from damage due to heat while soldering by first soldering the base to the board and then plugging in the IC later.IC bases are also useful if you want to reuse ICs without the need to desolder them each time.