The Free On-line Dictionary of Computing (30 December 2018):

Socket 7

    A physical and electrical specification
   for the x86 processor socket matching the pins on Pentium
   microprocessors manufactured by Intel, and compatibles
   made by Cyrix, AMD and others.  Any CPU chip conforming
   to this specification can be plugged into any conforming
   motherboard.

   Supported processors include: 2.5V - 3.5V Pentiums 75-233
   MHz, AMD K5 through K6, Cyrix 6x86 (and MX) P120 - P233.

   Socket 7 uses a SPGA socket, either a 296 pin LIF or a 321
   pin ZIF arranged as 37x37 or 19x19 (depending on who you
   speak to!).

   See also Super 7.

   Intel's Pentium II processor uses Slot 1 mounting.

   [Pin-out?]

   (1999-08-29)