... welding 100% qualified. Roller Sealing:Our roller Sealing have 3 type , Including TK , TKII, DTII . All the sealing use double labyrinth ... use SKF, NSK, HRC, LYC,ZWZ brand and the sealing type have ZZ, 2RS, RS and so on . Bearing & Sealing Press ... the pressure sameness, so the roller turn unimpeded . Roller of belt conveyor