Hi, Mohan Shetty!
I'm sure that you know more about the product than anyone else here.
My suggestion would be for you to start a draft of such a letter here, without putting any contact information in it. If you do that, I'm sure that there will be those of us who'll be willing to come along and make suggestions as to how you might make improvements to it.
In your letter, you should describe what the product is, what it does and how it might be of value concerning what it does and how it might be of use to the potential customer, about the potential benefits. You then ask them politely, in the letter, for an opportunity to discuss those things with them.
If there is a place where the demonstration is to happen, you list when and where, also.
Via clicking on the following links, you'll find samples of ways that you might draft such a letter that you might then tailor to meet your needs. Sample Business Letters and Forms Free Sample Sales Letter: Example of How to Write a Persuasive Business Marketing Letter Introducing a sample introduction letter template tool to assist leaders. Letter Samples - Free Letter Templates - Personal and Business Letter Sample Business Letters and Forms Idea Cafe Small Business Archive: "Company introduction letter" Business introduction letter... Here's a sample business introduction letter. Mid-career Job Offer Letter Sample: Introduction and Sample Mid-career Job Offer Introduction Letters Sample business letters by Quazell