Clubround, as the name suggests, takes the Clubmaster's browline styling and rounds off the front — RX4246V's version pairs that round front with a 145mm acetate arm, which this aftermarket pair matches. The round front changes the hinge angle compared with the squarer Clubmaster models, so arms cut for those won't sit quite right here.

Round-front acetate arms like this one flex slightly more at the hinge with every use than a straighter, squarer arm would, which is normal and part of why the hinge barrel — not the acetate itself — is usually the first thing to loosen. If the arm is discolouring evenly or has a small hairline mark near the tip, that's cosmetic acetate ageing rather than a structural problem; an actually loose or cracked hinge is the real sign it's time to swap the arm.