5dcd15dd_ts_Standard___PayPal_Developer_mension_Based_Shipping_Charges_Description
[Name] height_unit [Required or Optional] Optional [Description] 
Unit of measure for the values specified by the height_x values. Allowable values are any values that you choose to provide. PayPal passes the value to your callback server in callback requests.
HTML Variables for PayPal Payments Standard - PayPal Developer