I reached out to highwave
I reached out to highwave customer service regarding the non-standard sizing of the mug openings hoping they'd have advice on how to make future purchases. Customer service said sizes are random since the items are hand molded and I should continue buying different colors in hopes of finding batches that will fit my infuser baskets. Highwave knows I'm struggling with their products/ item descriptions and their only answer is to just keep buying. I get compliments on my mug at work and have to tell my coworkers to be wary about buying their own from highwave.