People come in all shapes and sizes, so it’s no surprise that condoms do, too. Size matters – the right fit ensures that comfort levels and efficacy rates are in top shape. How so? For example, a condom that’s too small may lead to breakage (not to mention major discomfort!) due to it being too tight, while a condom that’s too big might slip off, reducing its effectiveness.

Reference: https://www.verywell.com/do-condom-sizes-really-matter-906750/