311,2mm (12 1/4″) He mata keri me ngā tapahi polycrystalline, me ngā pūwero waipēhi, e 5 ngā mata, he 19 mm te whānui o te tapahi, me te tinana maitai mō te keri i ngā toka rahi-waenga.

He tino pai te mata keri 311.2mm (12 1/4″) mō te keri toka rahi-waenga. Ka tukuna e ōna tapahi polycrystalline he pakeke tino pai me te ātete ki te kakahu, kia roa ai te ora mahi me te mahi tapahi pumau. Ka horoia pai e ngā pūwero waipēhi ngā para toka, ka ārai i te aukati me te pupuri i te tere keri. E rima ngā mata, ka tohatohahia te kaha tapahi kia ōrite, ka whakaiti i te wiri me te whakarei ake i te pumau. Ka arotau te diameter o te tapahi 19mm i te tango maramara, ā, ka tukuna e te tinana maitai he kaha hanganga teitei hei tu atu i ngā āhuatanga toka kino. Mā ēnei āhuatanga katoa ka whakanui ake i te pai o te keri, ka whakaiti i te wā kore mahi, ā, ka whakarite kia pono te mahi i roto i ngā hanganga toka-waenga.