Recent, horrific school shootings have triggered schools everywhere to beef up security. The latest move: Installing bulletproof whiteboards in classrooms. They can be used for writing out lesson plans on - and as a bulletproof shield in an emergency.

In fact, the special whiteboards are already in schools in North Dakota, Maryland, Pennsylvania and California. And countless other schools are buying them for $300 bucks a pop.

So, how exactly do the whiteboards work? They’re about a 2 feet square, and are made of a material that’s stronger than a police-issue bulletproof vest. The manufacturer claims they can be shot, karate kicked, stabbed, and whacked with a police baton — without being damaged. And they say it can make the difference between life and death for teachers and students during an attack.

But critics worry the whiteboards could backfire - and provide a false sense of security. For example, students and teachers could stay in threatening situations, thinking the whiteboard shield will protect them - instead of hiding or trying to escape.

But a lot of school administrators say it’s their responsibility to do anything they can to keep kids and teachers safe – and bulletproof whiteboards are just another layer of protection. And it’s not just bulletproof whiteboards that are flooding the school safety market. You can now buy bulletproof clipboards and bulletproof backpacks for anywhere from $30 bucks and up.