XP/XR series fans are primarily used with high flow situations. This includes drain tile, gravel or where settling has occurred beneath the floor.
These fans are slightly less powerful than the RP series fans, but can be snugged up closer to a wall since they are all 8.5" inches in diameter.
Note: Utility cords need to be purchased separately. The XP151 has 4" openings thus requiring either 4"x4" or 3"x4" rubber couplings for mounting. When in doubt 4" pipe is recommended for the XP151. Varmint guards are a must to protect your fans warranty.