This ball-pen is red.

这支圆珠笔是红色的。

youdao

He rooted about in all his drawers and found the lost ball-pen at last.

他在所有的抽屉里翻来翻去，最后终于找到了丢失的圆珠笔。

youdao

There was a tiny ball at the tip of the pen.

笔尖上有一个小球。

youdao

Different from Wacom's capacitive Bamboo Styluses available for iPad, iPhone and other touchscreens, the Bamboo Stylus feel delivers a powerful combination of "active" pen and sensor technology for a digital pen experience that emulates the feel of a traditional ball-point pen or pencil.

ENGADGET: Wacom outs the Bamboo Stylus Feel for adequately equipped devices, ships January 7th from $40

If you give up on tablet writing, you can replace the tip to convert the pen to an old-fashioned roller ball.

WSJ: Putting Pen to Tablet: Using a Stylus With an iPad or iPhone