An offer in writing to pay a particular sum of money, or to deliver a written instrument or specific personal property, if not accepted, is equivalent to the actual tender of the money, instrument, or property, subject, however, to the condition contained in section 538.7; but if the party to whom the tender is made desires an inspection of the instrument or property tendered, other than money, before making the party's determination, it shall be allowed the party on request.
Iowa Code § 538.6