Review on Enhance Your Power Transmission with PGN Slingshot Caliber Precision Bearing Products by Jorge Kehayas

I actually use them to add weight to cakes. Cake tin, dough, parchment paper, those little ball bearings. Depending on your test, it will leave small dents as they are quite heavy. 1 packet is enough for 1 layer in a 24 cm cake tin. It's probably good slingshot ammo too, I mean it's a weighted object of the same shape.