What it is A set of 4 battery adapter converter cases designed to connect three AA batteries together to a large D battery. Material and construction Made from environmentally friendly plastic and metal with precise workmanship. Sturdy and durable with good electrical conductivity for reliable power delivery. Configuration and compatibility Allows flexible configurations by using 1, 2, or 3 AA cells to suit different capacity needs. Designed to substitute a large D battery in compatible devices. Applications and use cases Electronics projects or everyday devices that normally use a D battery, when only AA cells are available. Emergency power needs during outages, camping, or outdoor activities. Quick power options in handheld devices such as flashlights, radios, or other 1.5V equipment in a kit. Performance and durability strength and strong toughness for dependable use over time. Conductive construction supports stable power delivery in practical applications. Package contents Includes 4 battery adapter converter cases. Practical notes Suitable for electronics and emergency situations where Dsized power is desired but AA cells are accessible. Keeps a compact, versatile power option ready for various devices without compromising build quality.