Dental Metal Impression Tray Pack of 10 Pcs.(L0,L1,L2,L3,L4 Size And U0,U1,U2,U3,U4 size) Indian Made. Impression tray Pack for Doctors / Students. Features and Use-Impression tray that serve to carry the impression material to the mouth & support it in the correct position while it is hardening. This type of the trays can be used for several patients & used for making primary impression. Immerse the tray in a solution of COE TRAY CLEANER and warm water for 15-30 minutes. Stub-born particles of alginate, compound, wax, etc. may then be removed by lightly brushing with a soft bristle brush. Whenever possible, trays should be stored dry.