Oli & Carol
Oli & Carol is a natural-material brand: its teethers are 100% natural Hevea rubber, molded in one solid piece with no valve hole, so no water or saliva can get sucked inside to grow mold - the failure mode that sinks many hollow rubber toys. They're hand-painted with food-grade pigments and are free of PVC, BPA, phthalates, and nitrosamines. Fully plastic-free and silicone-free; the only caveats are the food-grade paint and the usual natural-rubber latex-allergy note.
How clear are their specs?
States the toys are 100% natural rubber, one-piece with no holes, hand-painted with food-grade dyes, and free of PVC/BPA/phthalates/nitrosamines - the whole material and construction story is disclosed.