The A-Type plug is the most common plug format with a diameter of 1/4 inch (6.35 mm), widely used in domestic and semi-professional environments. In Brazil, it is universally known as P10 Plug.

The term "Jack" technically refers to the female connector, but it is common for people to use "P10 Jack" to refer to the male plug as well. It exists in versions with two or three terminals, known as: • TS (Tip-Sleeve): Has 2 terminals and is mainly used for unbalanced mono signals, such as in guitars, basses and other electric instruments. • TRS (Tip-Ring-Sleeve): Has 3 terminals and its most common uses are for: ◦ Unbalanced stereo signals (e.g., headphones).      ◦ Balanced mono signals (e.g., line connections on mixing consoles and semi-professional audio interfaces).

Incompatibility with the "Type B" Plug (B-Type Plug)Although the P10 (Type A) plug is physically similar to an older professional standard known as "Type B" (found in some professional patchbays), they are not compatible.

The tip of the P10 plug is more angled and can permanently damage a Type B female connector (jack). Similarly, a Type B plug will not work correctly in a P10 connector.

Miniature Version: The P2 PlugThere is a miniature version of this plug, with a diameter of 3.5 mm, which in Brazil is called a P2 Plug (or mini-jack). It also exists in TS and TRS formats and is widely used in cell phone headphones, microphone inputs on computers, and CV/Gate connections on modular synthesizers.