I am surprised no one has asked this before, shouldn't this be that all important question? I could not find very much information about it but one source said 6-9 inches and it can handle up to 2 inches thick. Mine is about 1.9 inches thick I want it to be 2.5 and I think it will fit so that source must be wrong. All information is welcome about any experiences you may have had or heard of. My friends say the longest they have had is 6" and it hit their cervix. What about when the woman is very very excited? how far can the cervix stretch? Are there any guys who are not able to fit in all the way? By how much, and what is your length? what about someone who is too thick? I think that would be less of a concern.