I own Tenga and Tenga Lite.  I suggest stay away from the Lite version, it so tight/small for some it don't fit, also its not very enjoyable feeling.
If u all haven't got one buy one to let your curiosity out.  Your GF not a sex toy to use everyday, and if u don't live in country that legal cheap girls are at.  Tenga, is the upgrade from using your hand.