Bluelab External Lockout With Alarm Box varo__315mm Glassware may have minute blemishes

Glassware may have minute blemishes that will not affect the function

Turn the handle counter clockwise to release pressure

and put the Rockwool tray into the solution

Basically this means they are plant foods that can be used in both hydroponic systems or as a liquid fertiliser for non hydroponic growing

Bluelab External Lockout With Alarm Box varo__315mm Glassware may have minute blemishesThis External Lockout & Alarm Box connects the Bluelab Pro Controller to external switches, like a float switch or greenhouse alarm system. Upon activation of the switches, the Bluelab Pro Controller is locked out, halting all dosing. It also features a built in alarm which can be disabled, plus an external alarm (horn or flashing light) that can be connected. Additionally, an external lockout sensor can be connected (e. g. water flow sensor) to