Yes it must, I loosen my hole up with a 10mm sound and use it to get lube in and then a 12mm goes in with lube ok, you will know what I mean when I say I can feel it hit the tight gland about 20mm in my bell end, I feel it pop and open up ok with the 12mm, I can then get a 13mm in but it takes a little time and effort for the gland to pop and open up to let it in, it feels good once it is in