This is quite simple to use. You put your finger in it so that the vibrating part touches your palm. Lube it up, stick it in and start to finger it. The vibrator will take care of the clitoris. It has a weak vibration on purpose. It is designed not to make you Orgasm quick but to make you want more and get more desperate every second you use it!
Get it and make fingering much more enjoyable!
It is used in couples. If you're doing solo, better to get some bullet vibrator.