I don’t know if a plastic one, but i have one that is stainless steel. It’s made for adults but the same company makes baby bottle nipples and they fit in the cap of the adult bottles. Doesn’t look baby but should travel well. I’ll try and grab a link for you.
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https://www.amazon.com/gp/aw/d/B019GCE30U?psc=1&ref=ppx_pop_mob_b_asin_title
https://www.amazon.com/gp/aw/d/B00Q8FAYCK?psc=1&ref=ppx_pop_mob_b_asin_title