When ordering a cylinder be 100% honest about you erection's current, ACTUAL length and girth.
Then choose one that is an inch or so longer, for starters. It will be a waste of your money to buy one that is a much larger size, that you aspire to.
Start out slow, patient and confident that you will increase your size to fit it, with a lot of time spent practicing. Then later on, after you have made some gains in size, move up another "notch" to a larger sized cylinder.
Just my suggestion. (NOT an expert on this topic!)
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