26 x 20cm, no gusset. The drawstring creates a ruffled opening. It has a lining to prevent fraying on the inside. The lining is made of thin sheeting fabric, so it dries easily. Please understand that handmade items may have slight imperfections. Also, a separate listing for a matching gym bag in a different size is available (950 yen). If you would like to purchase multiple items, we can offer a combined discount, making the total 1500 yen. Please let us know in the comments.