Varieties of Huawei original boards for Optix 2500+ (Metro 3000) listed as below:
SS-RACK-2.0(T) T66 assembled cabinet (2000x600x600)
SS-RACK-2.2(T) T66 assembled cabinet (2200x600x600)
SS-RACK-2.6(T) T66 assembled cabinet (2600x600x600)
SS-SUBRACK SS6K8SUBRACK-2500+sub-rack (VIII)
SS-SCC master control board
SS-XCS XC Cross Connect and Clock processing board

SS-S16(S-16.1 SC) STM-16 optical interface board (S-16.1, SC)
SS-S16(S-16.2 SC) STM-16 optical interface board(S-16.2,SC)
SS-S16(L-16.1 SC) STM-16 optical interface board (L-16.1,SC)
SS-S16(L-16.2 SC) STM-16 optical interface board (L-16.2, SC)
SS-S16(Le-16.2 SC) STM-16 optical interface board (Le-16.2,SC)
SS-S16(V-16.2 SC) STM-16 optical interface board (V-16,SC)
SS-S16(U-16.2 SC) STM-16 optical interface board (U-16,SC)

SS-SL4(Ie-4 SC) STM-4 optical interface board (Ie-4,SC)
SS-SL4(S-4.1 SC) STM-4 optical interface board (S-4.1,SC)
SS-SL4(L-4.1/SC) 1xSTM-4 optical interface board (L-4.1,SC)
SS-SD4(Ie-4 SC) 2xSTM-4 optical interface board (Ie-4,SC)
SS-SD4(S-4.1 SC) 2xSTM-4 optical interface board(S-4.1,SC)
SS-SD4(L-4.1 SC) 2xSTM-4 optical interface board (L-4.1,SC)
SS-SD4(L-4.2 SC) 2xSTM-4 optical interface board (L-4.2,SC)

SS-SL1(S-1.1 SC) STM-1 optical interface board (S-1.1,SC)
SS-SL1(L-1.1 SC) STM-1 optical interface board (L-1.1,SC)
SS-SL1(L-1.2 SC) STM-1 optical interface board (L-1.2,SC)

SS-SD1(S-1.1 SC) 2xSTM-1 optical interface board (S-1.1,SC)
SS-SD1(L-1.1 SC) 2xSTM-1 optical interface board (L-1.1,SC)
SS-SD1(L-1.2 SC) 2xSTM-1 optical interface board (L-1.2,SC)
SS-SQ1(S-1.1 SC) 4xSTM-1 optical interface board (S-1.1,SC)

SS-PQ1(75 ) 63xE1 interface board (75 ohm)
SS-PQ1(120 ) 63xE1 interface board (120 ohm)
SS-E75(75/120) 63xE1/T1 access board (75/120ohm)
SS-E75S(75) 63xE1 changeover access board(75ohm)

SS-EFT Fast Ethernet VC-12/VC-3 transparent transmission board
SS-ET1 Fast Ethernet VC-12 transparent transmission board
SS-EMT8(RJ45) 8-port Ethernet access board(RJ45)
SS-EMS1 Fast/Gigabit Ethernet switching processing board
SS-EFS0 Fast Ethernet VC12/VC3 switching processing board
SS-EGT2 Gigabit Ethernet VC-4/VC-3 transparent transmission board

SS-BA2-D(14 SC) 2*Optical booster amplifier board (14dBm,SC)
SS-BPA(14/-37 SC) Optical booster & pre-amplifier board (14/-37dBm,SC)
SS-BA2-S(14 SC) single Optical booster amplifier board (14dBm,SC)
SS-BA2-S(17 SC) single Optical booster amplifier board (17dBm,SC)
SS-BA2-D(17 SC) dual Optical booster amplifier board (17dBm,SC)
SS-BA2-D(14/17 SC) dual Optical booster amplifier board (14/17dBm,SC)
SS-BPA(17/-37 SC) Optical booster & pre-amplifier board (17/-37dBm,SC)