Yes, the official Commodore trapdoor ram expansions were encased in metal shielding. It will be a standard 512KB fast ram expansion for the A500, giving the A500 a total of 1MB.

The A501 was A500 specific and should have a RTC battery backed clock included. Whereas the A501+ ram expansion was for the A500+ and didn't as the A500+ already has a clock built in.

It would be worth you removing it and opening it up as the clock battery is the type that can leak and cause damage, so it is worth checking this and removing the battery with some wire snips if it is leaking.