Very easy to install and adjust thanks to the quick clips and well-placed adjustment buckles. The materials are both lightweight and durable. Our 10-month-old dog, Jessie, is a medium-sized dog (female German Shepherd/Golden Retriever mix, about 40 pounds), and the backpack doesn't take up much space. The number of compartments is sufficient. We live on farmland and use the Front Range™ Day Pack almost every day. It's truly a well-designed product.