If the WAI-OC3-4SS you're looking at is the 4-Port STS-3c/STM-1 Single-Mode Fiber Port Adapter Module (a.k.a. 4-Port OC-3c/STM-1 SMF-Intermediate Reach Port Adapter Module), and it says "155 SM" on the front, then:
TX min: -15.0dBm
TX max: -8.0dBm
RX min: -27.0dBm
RX max: -8.0dBm
Output Center Wavelentgh: 1261nm to 1360nm
Link Loss Budget: (-15-(-27))=(-15+27)=12dB
Min. attenuation: (-8-(-8))=(-8+8)=0dB ==>not required
If it's the WAI-OC3-4SSLR 4-Port STS-3c/STM-1 Single-Mode Long Reach Port Adapter Module (a.k.a. 4-Port OC-3c/STM-1 SMF-Long Reach Port Adapter Module), and it says "155 LR" on the front, then:
TX min: -5.0dBm
TX max: 0.0dBm
RX min: -34.0dBm
RX max: -10.0dBm
Output Center Wavelentgh: 1281nm to 1380nm
Link Loss Budget: (-5-(-34))=(-5+34)=29dB
Min. attenuation: (0-(-10))=(0+10)=10dB ==>required!
Here's the link to the numbers:
http://www.cisco.com/en/US/products/hw/switches/ps718/products_installation_guide_chapter09186a00800eda11.html#26619
Hope this helps.