Where to find 58mm filter stack caps?

[Edwin]

Anyone has any idea where can I find these filter caps? Been asking around Peninsula area but in vain...

 

[jasonpgc]

Anyone has any idea where can I find these filter caps? Been asking around Peninsula area but in vain...

Can Try to DIY.

If really cannot find, buy a normal lens cap for the top most filter. Then buy a plastic filter, for example Hoya Softener Filter and screw on to the Bottom most filter.