They are barista standard because they replicate standard takeaway sizes and fit under the group heads of most espresso machines. When espresso based coffee is made in your KeepCup the crema remains intact and the portioning of milk to coffee will be correct.
Many small acts can make a phenomenal difference.
KeepCups are made from plastic so they are lightweight, easy to carry and have low embodied energy in manufacture.
They are BPA free and non-toxic.
KeepCups are dishwasher safe, microwavable and splash proof.
KeepCups fit into most car cup holders and many bicycle bottle holders.