Check the listing for details. Auto Trickler Reducing Insert Set. Condition: New. Listed at 24.99 USD. Reducing insert set for all Auto Trickler variants. Works to reduce powder overthrows for more uniform charge weights. The inserts are a tapered fit into your Auto Trickler discharge tube. Just twist them in and go. There is a large ID and slightly smaller ID insert in the set. The larger internal diameter insert works best with extruded powders, ie. Varget/H4350. The small ID inserts works good with smaller kernel type powders, short cut or ball/spherical type stuff. This is the general consensus among users, but you might find one insert works better for your particular powder, that’s why you get them both. You may have seen these on various shooting related forums as I've been making them for years now. Each insert is 100% hand made on a manual lathe, right here in the USA.