Anal toys for guys

My man and I just started exploring more things and I have found he enjoys when I'm giving head or sucking on his balls if I stick a finger inside and rub the prostate. Gives him a very intense orgasm, and I love knowing how much I'm pleasing him. But sometime I have a hard time because I have small hands and fingers to hit the spot enough, what are good toys for this? I don't want anything wider than my finger tho