hi guys had the ot out today and have given me some ideas to help my son with sensory issues as he likes deep pressure the ot suggested a weighted backpack I've looked on the Internet and online sensory shops but cannot find weighted backpacks has anyone ever came across these or know where I could get one I'm waiting for the ot to send me an email on what else I need to get but if any of you lovely lot could help on the backpack would be really great full