Agreement to make joint or mutual wills. H and W are husband and wife and are the owners in joint tenancy of _________ and the parties also hold and have agreed to hold as joint owners all other property which they now own or may later acquire while both parties are living, so that upon the death of one their entire estate becomes the sole and exclusive property of the survivor, and the parties are now _________ years of age and are uncertain as to who shall be the survivor and have considered the ultimate disposition of their joint property after the death of the survivor, and have mutually agreed to a joint disposition of their properties, effective upon the death of the survivor, to _________[e.g., children of the parties], as specified: 1. That immediately upon the execution and delivery of this agreement the parties shall make, publish and declare the last will and testament in the joint form set forth in Exhibit A annexed to and made a part of this agreement, as their joint last will and testament. 2. That each party expressly covenants with the other not to revoke, cancel, annul, modify, amend or change the last will and testament, either in whole or in part, during the life of either party at any time, and covenants that both will permit the will to stand irrevocably up to the time of their deaths. Provided, that nothing in this instrument shall be construed to prevent the parties from making a disposition of any of the joint property by joint action of the parties while both are living, and the survivor may make a sale or transfer [other than by will] of the property, other than _________[e.g., farm and personalty thereon], for the survivor's own use and maintenance, and may convert _________[e.g., farm and personalty] into cash where, in good faith, necessary for the support of the survivor or to preserve or prevent loss of assets. In case of a sale, the survivor shall keep and preserve the balance so that the disposition of the last will and testament may be as nearly as possible carried out as intended by the parties.