備用矽膠橡膠O型環

Bought a few spares after my old ring started slipping, and these fit perfectly into the grip groove. The silicone is soft yet holds its shape well, so the pen feels snug again without any wobble.

My pen's original ring wore out after years of use, and these silicone replacements fit perfectly into the cap's groove. The individual packaging means I could buy exactly the few I needed without wasting extras.

Swapping these into the grip was fiddly, but the silicone is soft enough that they seated without tearing. They’ve held their shape perfectly in the cap after a week of daily use.