1x Square Root Control ‘PotSock’ for a square 8.5 L or 15 L pot as used with easy2grow, 1Pot, and Auto8 modules. 

The PotSock is fitted over the bottom of the pot, gold face up, before adding substrates and plants.

PotSocks help to prevent roots from leaving the pot and heading towards the AQUAvalve. They are highly effective due to the special metallic gold coating.