Review on PH60F Replacement Pocket Powered ZenTest by Michael Zambrano

This rating applies to all ATVs (AAAA). This is the tip that you should order when purchasing the pen. I've tried many pens - the glass sensor hits hard. I recommend you just live with it and pay the extra $30 now - the original will break - not if, but when. We grow polyploids indoors, we don't need highly sensitive scientific equipment, we need more reliability. This works great! It has a low profile, flat sensor that is small and well protected. I'm planning on getting a $130 PH60S-E (Spear) so I can test the soil pH as well - looks like it can't be broken.