I had ordered this little whistle because my old something is heavy and unwieldy, This is also easy and they may be sometimes hold in your mouth to constantly hold it with one hand without .. Draws well and the head is smoking not too warm when. oh yeah ... a 9 mm filters can also use!
Addendum, I order nevertheless another whistle, this one can not properly clean as one with these Minibürstchen not coming in! So it is often clogged ... I use my compressed air gun to do so. :))
