Un/Limited (U/L) is a fully waterproof and size adjustable backpack tailored to the needs of an urban slow cyclist. This project aims to demonstrate the unlimited and limited requirements of space and material through a daily backpack. It can both expand to accommodate unexpected items and compress to keep the backpack streamlined to allow for better mobility. Following the design philosophy for 'design of reduction', the backpack is sealed by heat welding and made of mono-material DuPont Hytrel, or similar recyclable thermoplastic elastomers with different levels of hardness. This feature is in stark contrast to the backpacks on the market today, which are multi-material and hard to recycle.