This is a 1 piece 4 inch TPR Medical Double Caster with universal wheel, screw rod and hole, model B2. Designed for medical environments, it provides reliable mobility for carts, trolleys and other equipment that require easy upgrade or replacement of wheels. Key benefits Improves mobility of medical equipment: provides smooth, stable movement for carts and trolleys in clinical settings. Versatile mounting options: screw rod and hole design allow straightforward installation on compatible frames. Universal compatibility: the double caster and universal wheel configuration are suitable for a variety of equipment mounting styles. Compact 4 inch size: compact footprint that fits many standard equipment bases without adding excessive height. Medical grade construction: designed with materials suitable for hospital and clinic use. Key attributes Size: 4 inch wheel diameter Material: TPR (thermoplastic rubber) Configuration: double caster with universal wheel Mounting: screw rod and hole included Model: B2 Quantity: 1 piece Intended use: medical and clinical equipment requiring mobile caster upgrades Applications and use cases Replacing or upgrading wheels on medical carts, instrument trolleys, or supply carts to improve maneuverability in patient care areas. Installing on bedside equipment stands or small mobile devices that use a screw rod and hole mounting system for easier repositioning. Retrofitting clinical transport equipment with a universal mounting wheel to enhance pushability and reduce manual effort during rounds. Notes This description reflects the product as described in the title: a 1 piece 4 inch TPR Medical Double Caster with universal wheel, screw rod and hole, model B2.