The World’s Only Fold Up Door Chock was originally designed by a firefighter for emergency services. Fat IvanÂ& Reg; proves vital for many fields including Fire, Police, Commercial, Residential, Hotel/Motel and all deliveries. The easy one-handed operation opens quickly for insertion and never slips off hinge, guaranteed. Just place Fat IvanÂ& Reg; on any hinge, top, middle or bottom; then let it go and walk right through. FatIvanÂ& Reg; folds up quickly and stores in any space. You can also attach it to any metal surface with the embedded magnets. Safe, Durable and Reliable, Fat IvanÂ& Reg; is convenient for everyone!