PurGro GroBot pH Probe, Industrial Replacement growing-accessories The Apron is made of

The Apron is made of a waxed cotton canvas that keeps particles from sticking

it is formulated to promote lush vegetation

and sturdy design

Ideal as an additive for organic tea mixtures

True IP65 protection against water and dust

PurGro GroBot pH Probe, Industrial Replacement growing-accessories The Apron is made ofThese don't look like the ones from the hydro store because they are double junction, flat surface pH probes typically used in chemical plants for process control. They last longer, stay cleaner and are built to mount in line inside your GroBot Evolution. Cost a few bucks more, but these are the good ones. Proudly made in the USA.