I was skeptical of Earthwell
I was skeptical of Earthwell as they lacked the typical, iconic caps that functioned as straws or open lid sippers. This was by far the closest that came to one and it works wonderfully. At the moment, alongside the 32oz thermos I got, it has not leaked (and I laid it on it's side for hours full of water). Maybe it gets worse as it ages, but at the moment, it's great. It also fits surprisingly well on my Thermaflask bottle so some cross branding mutation is cool.