Cov teeb meem tseem ceeb ntawm cov kav dej tsis zoo yog:
Cov kav dej tawg yooj yim. Conduit installation yog concealable project, ib zaug xau, tuaj yeem ua rau muaj kev cuam tshuam loj heev rau tag nrho qhov chaw nyob; Tsis tas li ntawd, hauv kev saib xyuas, nrhiav cov ntsiab lus xau tuaj yeem ua rau muaj kev puas tsuaj ntau thiab ntau yam tsis tsim nyog. Nws tseem yuav ua rau dej paug. Vim tsis muaj cov neeg siv khoom paub txog qhov tseem ceeb ntawm cov kav dej zoo, lawv xav tias nws yog qhov zoo dua los siv qee cov kav dej pheej yig. Tab sis, qhov zoo ntawm nws tus kheej ntawm ntau yam kev ua tsis zoo tsis yog Standard, thiab muaj teeb meem xws li cov hlau hnyav tshaj Standard Commonly, ib zaug ua rau HEAVY hlau mus rau qhov zoo, POISONE.