These are great machines and if they are making noise or not working right then the odds are very high the problem is just the belts. THREE BELT KIT: Two Drive Belts (2) and a Door belt (1) for a total of 3 BELTS for the following SONY CD Players - Changers: CDP-CX400 CDP-CX450, CDP-CX455 CDP-M333ES, CDP-M400CS, CDP-M555ES, CDP-CX777ES, CDP-CX985V, and CDP-CX995V. All packaged in our plastic bag and instructions including our phone number if you need help ALL Sony 400 CD Players have a total of three belts 2 Drive belts and 1 Door belt. Please READ OUR FEEDBACK then decide if you would like to buy from us. Also we WILL BE the fastest at Shipping your order. ALL orders received before 2PM Texas time will be taken to the Post Office the same day. We do this to make your shipping time one day less so you will get your order faster. We advise you not to remove CDs or take your Player apart until you receive our instructions as it will save you some time. When you read the Product Ratings make sure "TRAP538" is at the end of each rating, that way you know it is from us. Super Simple Instructions are sent with your order. If you have a problem or need help installing the belt, you can call me and I can walk you through the steps. "SONY" across the picture in some other ads, means nothing because Sony has not made SONY Belts for the 400 CD Player in years. Also don't be fooled by all those different model numbers for a 400 CD Player.