Classroom Sentry is a remote Aerosol dispenser system. It uses a non-lethal pepper spray and teargas mix to deter an attacker. Classroom Sentry is our first attempt to give some control back to students and teachers in a challenging scenario. Its compact size allows you to mount it over a closed classroom door. You can build it yourself in eight simple steps. It takes about five minutes to build and has five components. Please watch the DIY video below for information to build a Classroom Sentry.
 
Please note: You are purchasing the plastic shell only. Other required components are not provided and should be purchased seperately from third party vendors. 
 
 
You need the components below to complete the assembly. Approx. cost of components is USD 90.
Amazon List of required components
Items in the above list are
PQ12-S Micro Linear Actuator 20mm, 4lbs Max Force, (Includes Hardware Kit) Get the 12V version.
SABRE Advanced Pepper Spray, 3-in-1 Formula Contains Maximum Strength Pepper Spray, CS Military Tear Gas and UV Marking Dye, Compact Belt Clip for Easy Carry and Fast Access, 25 Bursts, 10-Foot Range. Plastic shell is designed for the dimensions of this pepper spray.
Actuonix PQ12 Cable Adapter Please check Actuonix shop if the item is not available elsewhere
12 Volt 2A Power Adapter Supply, AC 100-240V to DC 12 V Power Supply Transformer Charger 2.5mm X 5.5mm Wall Plug for DC12V Light Security CCTV Camera. Buy one which comes with a barrel connector
Vinyl fencing 45 degree adapter. You may purchase the 3D files for 45 degree adapter here
Kasa Smart Plug Ultra Mini 15A, Smart Home Wi-Fi Outlet Works with Alexa, Google Home & IFTTT, No Hub Required, UL Certified, 2.4G WiFi Only, 1-Pack(EP10), White (Optional) Allows you to control the unit using alexa or kasa app from smart phone. (You may use the smart plug of your choice.)