After several months the modification can be quite noticeable and permanent changes have occurred. At the one-year mark you have probably reached maximum of length but expansion in girth may continue to occur. That is pretty dramatic. If you discontinue pumping you will retain much of the modification but occasional pumping will ensure that your results remain. Pumping does not result in erectile dysfunction, quite the opposite.
Many doctors treat erectile dysfunction with a penis pump.
Once you have pumped the penis as full as possible, a cock strap is placed at the base of the cock and balls. This forces the blood to remain in the penis, keeping it engorged. I think it is the responsibility of every male out there to get busy and make those cocks bigger and better for those of us that use them. BME has many examples of body modification and body art by CM HURT in the archives, mostly under the Extreme section. BME and CM HURT will be offering a fine selection of video tapes displaying the techniques described above, showcased in a hot BDSM setting, in the BME Store section, soon.