If any contract delivered or issued for delivery in this state provides for payment of benefits in variable amounts, it shall contain a statement of the essential features of the procedure to be followed by the insurance company in determining the dollar amounts of such variable benefits. Any such contract under which the benefits vary to reflect investment experience, including a group contract and any certificate in evidence of variable benefits issued thereunder, shall state that such dollar amount will so vary and shall contain on its first page a statement that the benefits thereunder are on a variable basis.