The most noticeable feature of any strap-on setup is the dildo used. A wide variety of dildos are available, and while the choices may be limited by the type of harness in use, generally one can choose from several common types.

This section discusses the shape and features of the penetrating end of the dildo, not of the entire dildo or how it’s attached, which can be found in the section on dildo attachment methods for the double dildo and strapless dildo.

“Standard”

The “standard” dildo has a non-tapered or slightly tapered shaft, and often has an enlarged head, similar to a penis. The shaft may be slightly curved, but if it is strongly curved, it is often classified as a g-spot/prostate dildo as well. This type is by far the most popular, both for vaginal and anal use, although some beginners prefer a probe-type dildo. Depending on the type of harness the dildo is meant for, it may have molded testicles as part of the base, which many people say gives more pleasure and helps keep the dildo from “bottoming out.” Standard dildos are the most common by a large margin, and are available in virtually any length and width, material, texture, etc.

Probe

A probe dildo is often highly tapered, and many resemble a cone in overall shape, or may have a narrow diameter its entire length, although ones resembling an elongated butt plug are also common, their defining feature being a bulb in the middle which tapers down again towards the harness before flaring wider. These dildos are often advertised as being for beginners, especially newcomers to pegging, who may find a narrow, tapered dildo easier to start with if they have never had anal penetration before. Many people find that once they are familiar with the activity, the probe dildos are inadequate and unsatisfying, and purchase a standard dildo to use with their harness. Due to this, many kits include both a probe dildo and a standard dildo, so it is not necessary to purchase another.

G-spot and prostate

Dildos designed for g-spot or prostate stimulation often have a sharp upwards curve at the head, or gradual but still strong curvature the entire length. When used in many sexual positions, the curve causes strong pressure against the g-spot in women or the prostate in men. Some men report that strong prostate stimulation is important for an anal orgasm, while others report it as a distraction rather than a help. When using one of these dildos for the first time, care should be taken at first to make sure it’s comfortable for the receiver, as the strong bend can be difficult to insert or control. For many positions, such as doggy style, the curved tip should point downwards, as otherwise it points in the wrong direction for either g-spot or prostate stimulation.

Textured

For added stimulation, many dildos for harness use are manufactured with bulbs along their length, or having ripples, bumps, or other shapes on the surface to increase the stimulation given to the receiver. A bulbous dildo causes repeated expansion of the vaginal opening when used for vaginal penetration or of the anus when used for anal penetration, and causes a unique pulsating effect and additional stimulation. Ripples along the length of the dildo increase friction and cause a washboard effect, which some people find increases their pleasure, while others find tend to cause numbness. Individual bumps or a water droplet texture on the shaft also causes extra stimulation, and often avoids the washboard effect of evenly spaced ripples. Some dildos modeled to be realistic penises contain very heavy vein textures on the surface, causing a similar effect.

Vibrating and rotating

Some dildos, especially recent ones, may have rotating beads along the shaft, a wiggling shaft, vibrating ticklers or other clitoral stimulation devices, or other features to give more pleasure to the user. While their effectiveness is a matter of opinion, they are becoming increasingly popular. An inexpensive design is basically a standard rabbit vibrator designed for harness use (often exactly the same toy with a slightly different base), while more expensive dildos are designed from the ground-up for harness use and are usually superior. Rotating beads provide extra stimulation of the vulva and vaginal opening when used for vaginal penetration or stimulation of the anus when used for anal penetration, while the various clitoral stimulation devices are generally intended only for vaginal intercourse. These dildos are often bulky or heavy, and like all other vibrators need a power source (usually batteries in a pack that clips onto the harness or slips into a pocket on it), but can provide additional stimulation for those who desire it.

Double penetration

Double penetration dildos are generally two dildos molded onto a common base, designed for simultaneous vaginal and anal penetration or simultaneous vaginal and vaginal penetration, not to be confused with a man using a strap-on along with his penis for double penetration, which is discussed below. A typical double-penetration dildo has a longer, thicker main shaft for vaginal penetration, and a shorter, thinner, often more curved shaft for anal penetration, although while rare, dildos with the anal shaft being equally as large as the vaginal shaft are available for women who find a larger anal dildo more satisfying. These dildos tend to greatly limit the possible positions they are used in, as the angle has to be right for both vaginal and anal penetration when thrusting, however they can provide a unique experience for couples to try.

Inflatable enema nozzle

Many specialty dildos are available, such as ones that expand when an attached inflator bulb is squeezed, ejaculate warm water on demand by compressing a reservoir, or function as enema nozzles, allowing an enema to be given while using the strap-on for anal intercourse. Inflatable dildos generally expand in girth when inflated (they usually come with a simple hand-squeeze inflator bulb), allowing the dildo to keep expanding during intercourse as the receiver slowly stretches, giving a unique completely filled feeling which is hard to obtain using normal dildos. Ejaculating dildos contain a squeeze bulb or other reservoir, which when filled with hot water beforehand, allows the wearer to “come” into the receiver at the proper moment. Enema nozzle dildos contain tubing connections, and when used for anal penetration (most often with silicone lube, as water soluble lube would quickly break down when combined with an enema) allow the receiver to receive an enema during intercourse. Some BDSM mistresses specialize in offering this service. A relatively new product in this field is dildos with electrodes for erotic electrostimulation, further increasing the range of sensations the receiver can experience.

Penis extensions

Hollow dildos are often sold as penis extensions, but the most common use is for men with erectile dysfunction. The penis is inserted into the hollow inside of the dildo, then the harness is put on, allowing the man to penetrate his partner with the dildo, the thrusting of which is transferred to his penis.

To Be Continued…