Enough : Package includes12pcs blackout sleeves, which are sufficient to use in daily system or replace. [WIDE RANGE OF USES]hydroponics is the most passive form of hydroponics,can be used on a of plants such as pods,mint,,spider plant,ivy,etc.Help you enjoy the of growing plants.There are 12 in the set, enough for daily use and replacement. Easy to Control Light: jar sleeves allow you control light for different sprout seeds. It can keep light out of your container when use, and most green sprouts also indirect sunlight. Product Size: The blackout sleeves fit 32oz wide mouth jars quite well, it's not suggest to use on other size of jars. Practical and Convenient: easy to use, you can only put the jar into the sleeve ,then tighten the adjustable buckle. size: 10 x 16cm Material: Polyester colour: Black Package Contents: 12 x Blackout Sleeves Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.