Ishelufu eliguquguqukayo lokusunduza noma ishelufu le-roller elinebha yelebula lentengo,Khulisa ulwazi lokuthenga kwamakhasimende,esetshenziswa kabanzi eshalofini le-gravity roller noma amaracks okubonisa ugwayi kanye nesistimu yokuphusha ishelufu.
Ikhwalithi ethembekile nolwazi oluhlukile.