GS-RAM III
Up to 4 MEG on one card in 1 MEG increments. With an optional 2 MEG piggyback card, GS-RAM III can be expanded to 6 MEG, and is fully DMA (direct memory access) compatible.
Manuals & files
Opens on ae.applearchives.com (not rehosted here).
Source page: https://ae.applearchives.com/apple_iigs/gs-ram_iii_2/