Pentel Slicci Gel Ink Pen - 0.4 mm - Royal Blue Ink

I have several of these in .4 mm size in verious colors and I really like them. In general I feel they are smoother writing than the hi-tec pens, however they are shorter and thinner which makes them less comfortable to write with. At first my fingers would cramp-up but after I used them for some time, my hand adjusted to the thinner barrel, and they are not as short as the slick knock which was very uncomfortable for me especially with the metal clip. All in all I will be ordering more and I do recommend these to others. Are these refillable like the Hi-Tec? If not, they are faily expensive for a disposable especially since they contain less ink than Hi-tec.