https://www.protecstyle.com/M407 ※ I believe this product is not widely available. Please consider purchasing it before someone else does! ・This is a mute bag for trombones, but I used it to carry trumpet mutes, accessories, and sheet music. While the M408 for trumpets can't hold sheet music, this one can store sheet music, as well as textbooks, simultaneously. ・The lid has a double layer, and the inner lid serves as a mute holder that can be used during performances. ・It can be attached to commercially available carry carts. ・Includes a shoulder strap. ＜Specifications＞ ・Internal Dimensions: 50.8 x 31.8 x 27.9cm ・Bag Weight: 2.11kg ・External Dimensions: 55.9 x 35.6 x 35.6cm ・Front Pocket Internal Dimensions: 38.1 x 30.5 x 2.5cm ・Right Pocket Internal Dimensions: 22.9 x 29.2 x 2.5cm ・Left Pocket Internal Dimensions: 24.1 x 29.2 x 2.5cm