Never seen Thu on3 on left before and other maybe for a drill press or something. I just bought like 150 at least mostly USA drill bits from my local flea market all sizes on top of what I already had I've got more than a lifetime worth for myself. At my local flea market there's a guy that sells USA made drill bits for $1 each still in packs he also has Makita and Milwaukee drill bits well did I cleaned him out on those can't beat the price for Thu bigger sizes I'd say I bought 100 of them and have another 100 loose ones I'm loaded with drill hits. Hope you learn what those are good luck.