Review on Optimize CO2 Monitoring: JARDLI Glass Drop Checker for Planted Aquarium Tanks by Tracy Graham

This is a beautiful plaid pattern, much more aesthetic than others I've seen. I haven't had to change my 4x liquid yet, but without the use of a dropper I think it might be a bit more difficult than a traditional cleaning design. However, this little extra work every few months (if that is the case) is worth the daily visual stimulus in my aquarium.