A dual stim toy is one that has two different points of stimulation. The classic example is the rabbit vibrator, which consists of a dildo portion for vaginal insertion and ‘bunny ears’ for clitoral stimulation. But there are other varieties of dual stim toys such as a combo cockring/prostate stim or a double dildo (see some examples below).
A common issue with dual stim toys is that they don’t always mesh with anatomical reality and bearing in mind that bodies are diverse, a rabbit toy that fits one vulva will not necessarily fit the next. Another problem is that usually you can’t independently manoeuvre the two stim points, so you have to make do with the same pressure/vibration/motion for both areas.
If you have the ability, I’d recommend using two specifically designed toys rather than a dual stim device. However, if you’re a person with limited mobility or a limited number of hands, a dual stim toy may be absolutely ideal for you. If you do decide to try a dual stim device, look for something that is flexible and therefore more likely to fit your body. Good sex toys can be pretty pricy so look at reviews of the device before making a big purchase.