sextant,

云知声与百分点联合发布分布式操作系统的"发行版":sextant
the nautical sextant [平装]
六分仪表(sextant)
【中商海外直订】how to use plastic sextants: with appli.
sextant Ⅱ经皮椎弓根螺钉系统