This E 15.- camera has the IR block filter in back of the lens. The sensor is not attached to the mother board, so it has to be held in place with a wrench (15) when unscrewing the lens, which is weakly glued to the 12 mm holder. It is possible to do this mod without detaching ribbon cables , as the inner frame can be tilted halfway out. I use the 2 filters from 3 D glasses: cyan and red, and an IR filter ( a plastic filter from Edmund optics, but an old floppy disk would work).
The filter can be permanently glued in back of the lens, but i decided to buy a 37 mm filter kit, with 10 mostly rather useless filters. The ring holding the glass can be removed with a putty knife ground to 37 mm width.