I pump between 3 - 4hg and often in excess of 8 hours. I'm also restoring my foreskin and the advice for that is low sustained tension. I’ve heard that a number of other restorers have also experienced gains in the length of their penises while restoring. Likewise guys over at thunders are now adopting low tension for gains. If anything, high tension can have an adverse effect on gains, so I’m quite happy with 3 – 4.