Try one of our Ring Master cock rings:

Our newest silicone Ring Masters are created for the pleasure and satisfaction of both parties. The intent of these vibrating rings is for both parties to feel vibrating stimulation while participating in traditional and experimental positions of sex. (i.e:  Missionary position, on all fours position, scissoring position, etc.) For gentleman the ring will vibrate the shaft and balls of the gentleman wearing the ring. Allowing the gentleman to maintain and build a highly satisfying erection. For the woman or recipient receiving the penetration, the ring will vibrate the clitoris or anal opening of their body; creating highly stimulated orgasms and highly climatic arousals. 

All you have to do is follow a couple easy steps to use this stimulating item. First clean the silicone ring in a warm water solution and allow the toy to air dry. Next place the vibrating bullet(s) in their designated slots. Then lubricate the inner ring of the toy and the shaft of the penis and or balls to slide the toy on the penis before it is erect. Once you have achieved these steps you are now ready for pleasurable penetration.