Very extensive, if you just mean normal size/shape/color, etc. You can load different males which have different penis shapes, or get into the customizable Male Morph menu where you could (with some wading through way too many options) create pretty much any shape. There is also a place where users post mods, for example for non-circumcised (which is one thing that is missing as a default). You can also download some unusual shape morphs. So, by default, just load different males and find the penis you want, or dive deeper by downloading community mods or using the Edit mode Male Atom -> Male Morphs area (where there are thousands or tens of thousands of morphs).