This RS-232 Female icon is made in Material Design style developed by Google. This style is based on extremely simplified shapes, thin two-pixel lines, and is optimized for 24x24 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 4,900 icons, all in the same style and quality.
This looks like an upside down trapezoid. The corners of the trapezoid are rounded. In the center of the trapezoid are nine circles. There's a line of five circles near the top of the trapezoid, and a line of four circles near the bottom.