Pelvic floor exercises is also known as Kegel Exercise. It is named after a renown doctor called Dr. Arnold Kegel. This exercise involves relaxing and contracting the muscles that form part of the pelvic floor. By strengthening the pelvic floor muscles, it can improve the muscle tone which can help pregnant women in preparing for vaginal childbirth.

Pelvic floor exercise also good for treating vaginal prolapse for women. Kegel exercises may be beneficial in treating urinary incontinence in women as well as man. Kegel exercises may also increase sexual gratification (women) and aid in reducing premature ejaculation (men).

Kegel exercise is done by using a tool called Kegel exerciser. This kind of device designed to be used by women to exercise the pubococcygeus muscle .

There are 3 types of kegel devices commonly used, There are rubber bulbs,  barbells and springs. The device that is normally made of polished solid stainless steel, it is cylindrical in shape, with a rounded bulge at each end.

Spring devices are made of plastic, with removable springs to allow progressive resistance. These allow pressing directly against resistance. An advantage of rubber bulb devices is that they provide visual feedback (via a gauge) of how much pressure is being applied.

Although it is the most natural way to tighten those muscles but it does have drawbacks too such as the need of discipline to perform the exercise on a regular basis. The improvement is not instantly, and it could take weeks or months. You will need to purchase the exerciser where the price range from 40 bucks to over 100 bucks.
Here is an alternative to kegel exercises which is created to tighten the vagina and increase sensitivity quickly. Using Intivar will provide an instant tightening sensation, therefore can be used on its own to tighten the vagina.

Click Here for More Detail

You may also interested in below posts:

Kegel Ball
Vaginal Looseness
Kegel Exercises for Women
Tighter Vagina
Stretched Vagina