... alloy body coated with three layers of glossy paint prevented from oxygenation.4. The high-carbon steel geer shaft works smartly ... Testing of Fire Building Materials. 8. Applicable for wood door,steel door,fire door,etc.9. Colour options: Silver, black, gold,white. ... full.13. Installation types: vertical, parallell, sliding-rail on the door.14. Self quality test for oil(temperature test), spring & ...