I've used this multiple times and it's kept the slave immobilized for as long as I've deemed necessary - face up and face down. Slip them under your mattress and your slave's going nowhere - the straps let you decide how tight you want to hold down or stretch your partner and it's yet to come loose once. I'd highly recommend them to anyone interested in restraints - beginner or experienced. Bondara sent this item to @UKDom10 free of charge, in exchange for a fair and honest review.