you sought technical advice go your way! I thank those who have posted reviews, I was looking for a puncher and as I am not pro DIY I trusted the comments :! result I am not disappointed I had the feeling that I am Superman! and yes is drilled into the stone as if it comes from the Arab guy! the first time I impressed my wife after 20 years of marriage !. I spent electric lines in a stone house He was a treat! 'Javais scheduled one week I am in one day! limit I am disappointed to have finished! I will make holes in hiding the neighbor because shame not to use my super spike filled every day