They use 1 pound charges of what looks like a plastic explosives. We actually use two now. One at the bottom of the hole and one at the top. They way the whole column of anfo gets lit before the to click moves.
Orange thing is the booster and the small skinny thing is the cap. This on is a electric cap which gets programmed to the correct time to go off.
The anfo is pretty awesome stuff. It has the fertilizer pellets suspended a expanding foam liquid. That way when they toss the plug in from the top the anfo expands into all the voids.
I get orica to fill the holes. They make everything to do the blasting for themselves. They have a proprietary blend for the emulsion and their caps and computer are their own design. I’m very happy with their product.