Where can I get the brackets that keep rear seats in place?

[Lyncho007]

Looking to put seat belts in the rear of my van and dont want seats to move. Anyone know where I can get the brackets that keep the rear seat foam in place on a bench seat/rock n roll bed?

I've seen them on lots of people's pictures of interiors but haven't seen them for sale!??

 

[Koppe]

cip 1 has a rear & middle seat bracket kit