It sounds like you are describing an adjustable GT mirror with a square shape, black color, and a claim of being a universal fit for all bikes. This type of accessory is commonly referred to as a "universal motorcycle mirror" designed to enhance the appearance of various motorcycle models while providing adjustability for improved visibility. Here's a brief description:

Adjustable GT Mirror Triangle Black:

Design: Features a square shape, which can add a distinctive and stylish look to the motorcycle.
Color: The mirrors are black, offering a sleek and neutral color that can complement various bike styles.
Adjustability: Typically designed with adjustable joints or swivels to allow riders to customize the mirror angle according to their preferences for better rearward visibility.
Universal Fit: Marketed as a universal mirror, meaning it is intended to fit a wide range of motorcycle models, providing flexibility for riders with different bikes.
Installation: Generally designed for easy installation, often with a simple clamp or mounting system.
Material: The mirror housing is likely made from durable materials such as plastic or metal to withstand vibrations and outdoor elements.
Aesthetics: Apart from functionality, the mirror may be designed to enhance the overall aesthetics of the motorcycle, contributing to a customized and appealing appearance.

ADJUSTABLE SHENAO GT SQUARE MIRROR