I can all only abrahten to buy this product !!! It is given with 7 mm diameter, but that's not right !! He has only 6.5 to 6.7 mm diameter! This is noticeable in my STRONG! I have a Bosch GluePen, drop the cartridges Always out with me. Because they are so short I have always quickly the next slide afterwards. :-( Not Schpart at the wrong end.