When I try to calibrate it reads error calibrate again. Its base has a broken latch. This will not interfere with the operation.The latch is used to carry the base or (Target Mask FD-A01) and Spectrodensitometer together. (no longer have broken latch pieces). I do not know enough about it to say its working or not. The Spectrodensitometer comes with the items listed below. Target Mask FD-A01 Pivoting Base Assembly. Power Adapter for Charging Internal Batteries. Downloaded and Printer Instruction Manual. Downloaded and Printed Two Sales Pamphlets.