Silver Rectangular Cufflinks Opart Circles. A beautiful pair of Silver Rectangular cufflinks with a deep engraved Opart Circular pattern. The Opart Circles Cufflinks have a swivel T-bar Fastening and are fully hallmarked. Made by our Silversmith in the UK and presented in a smart cufflink box. Please note, the cufflink box might vary in colour or shape depending on availability.