https://www.amazon.com/dp/B004X4J6EU?ref=nb_sb_ss_w_as-ypp-ro-model_ypp_ro_model_k0_1_25&crid=1BQTLTJEPP5EV&sprefix=frio+insulin+cooling+case I use these Frio wallets! I like them because all I really need is some cold water to refresh them rather than needing a fridge/ice pack, and they usually stay cool for 3-4 days. One drawback I have noticed is that they can get kind of mildew-y over time but I also could just not be taking care of them well