KwokwaiWu, mine is actually smaller than it looks on the pictures.
I used two table spoons of flour per load to test these mines. Works good. Powder didn't get on my pants at all but cloud was big enough and sound was loud enough to know that I was "dead". Powder also left white circle around the mine after "detonation". What I found that most of powder ended up on my boot because my foot blocked a lot of holes when I steped directly on the mine. Result was a lot better when I steped on the side and left more holes open.
P.S I only used propaine. It does louder bang with CO2.