yeah i think its 2 deep, i used a 1.25 and that hurt like hell, stayed sore for about 4 days, i done the 1" pin saturday and no pain the next day, it definately makes all the difference, got my pins from medisave.co.uk
i hit my thighs last wednesday with test and eq, used a 1.25" pin and i hurt bad, took 4 days to ease the pain, this time i used just a 1 inch 24 ga pin and it was much better, only hurts a little now.