Apple has halted development of a compact Apple Pencil designed separately for the iPhone Duo just before mass production and has shifted to supporting the existing USB-C Apple Pencil, reports said.

NineToFiveMac reported on Sept. 20 that Apple had been developing a new Apple Pencil tailored to the iPhone Duo. The product was said to be smaller than the existing Apple Pencil and designed to attach magnetically near the iPhone Duo’s hinge. Apple was also said to have considered compatibility from the design stage so the iPhone Duo would support the Apple Pencil.

But Mark Gurman (마크 거먼), Bloomberg’s Apple reporter, said the stylus ran into technical problems before entering mass production. Apple ultimately stopped developing the dedicated compact Apple Pencil and changed course to support the existing USB-C Apple Pencil on the iPhone Duo. At the iPhone Duo launch event, Apple announced support for the USB-C Apple Pencil rather than a separate new stylus.

Still, Apple Pencil support for the iPhone Duo will not be available at launch. Apple is applying separate software and conducting internal testing so the USB-C Apple Pencil can be used on the iPhone Duo, and support is expected later this year. This was reported to be because the iPhone Duo was not originally designed on the assumption it would use the USB-C Apple Pencil.

It has not been confirmed exactly what technical issue occurred with the dedicated compact Apple Pencil. It is not known whether the problem lay with the stylus itself or arose when the iPhone Duo attached and charged it magnetically. If the issue is limited to the stylus, Apple could still reintroduce the accessory later.

Apple Pencil support on the iPhone Duo is currently limited to the USB-C model. Apple Pencil Pro is not supported. Apple plans to enable the USB-C Apple Pencil to be used on both the inner and outer displays of the iPhone Duo.