Stem adapter casters are a type of caster designed to be attached to equipment or furniture using a stem and an adapter. Unlike threaded stem casters, which screw directly into the object, stem adapter casters offer flexibility by providing a separate adapter piece. This adapter typically has a flat plate with holes for screws or bolts, making it easy to attach to the bottom of the object.

The stem adapter itself has a stem that fits into the caster's mounting socket. This design allows for a secure and often swiveling connection between the caster and the object. Stem adapter casters come in various styles and materials, offering options for different load capacities, floor surfaces, and mobility requirements.