Some of the rental companies

Some of the rental companies will require a deposit equal to the value of the gear. The deposit is authorized but not charged to a credit card. If the renter doesn’t return or damage has occurred, the charge is put through or adjusted in the case of damage.

99% of the time I wouldn’t rent my gear unless I went with it or I was assured – in writing – such a company had a valid insurance policy, and I would check it out thoroughly.