Product features: This product is made of polyester lycra spandex stretch cloth and elastic drawstring technology. The material is soft, comfortable, breathable and flexible, which can wrap the piano body to the back to avoid dust intrusion. Whether it is placed in a bag or performed, it is very protective for the piano when it is carried out! This product is divided into two specifications: One: 61/73/76 keys are divided into one specification, which is suitable for 61/73/76 key electronic organ/synthesizer of various brands in the market! Two: 88 keys are divided into one specification, which is suitable for 88-key electric pianos/synthesizers of various brands in the market; Both width and length can be used. Product weight: about 150g