Penis pumps are known to cause damage to the penis in the long term while extenders, as long as used correctly, are fairly safe. I would recommend that you read up on them first however (this is one of the leanding penis enlargement brands: http://www.sizegenetics.com) it will make you more comfortable about using them in the long term, know this at least, results do not come magically overnight for ANY form of successful penis enlargement.