3 "kev sib tsoo disc yog qhov tsim nyog rau kev sib tsoo pob zeb thiab terrazzo hauv pem teb, nws yog qhov yooj yim los hloov thiab tsis yooj yim ya mus thaum sib tsoo, Round hla ntug tuaj yeem so tawm hauv pem teb lippage thiab zoo heev txo cov khawb hauv pem teb. Nws muaj 6 ntu ( 7.5mm qhov siab) thiab ruaj khov heev.