Write a letter in 130-150 words. Write a sales letter to an old customer who placed an order with you two years ago,and draw his attention to some new products which represent a great improvement on some of the models he has sold successfully.Your letter should cover the following particulars: ·对方是你公司的老客户，曾大批订购你公司生产的开关装置（switchgear），之后就没有再订过货。 ·告知客户你公司最近在市场推出一种最新高压（high voltage）开关装置，并介绍新产品的特点。 ·随函寄上产品规格及价格表供对方参考，并强调尽快订货的重要性。

Dear Sirs,
Two years ago we had the pleasure of supplying you with a number of switchgear. Since then we heave received no order form you. Perhaps our previous did not fit your requirements.
Now we wish to inform you that we have just introduced our latest high voltage switchgear on to the market. Our research engineers have finally come up with the answer to some of those problems you had with high voltage currents. The present product is insulated with a special resin which is as tough as metal,cracking-resistant,and very economical,and has passed test after test run by our engineers. We are enclosing specifications and a price list for you consideration and hope to receive an early order from you as other buyers are showing their great interest in this product.
Yours sincerely,

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