There are two different Ridgid models in the 4 gal, 5hp setup. They look almost identical, but there are several differences. The stand-alone model (WD4050) has significantly fewer attachments. It also has a more powerful motor. It has a 9 amp motor, while the wall-mountable unit (SG4000) only has a 8.5 amp motor. The stand-alone unit will not fit into the wall mount cradle. The mountable units have the blower feature "removed" because of safety regulations, and interestingly are not marketed as wet/dry vacs, presumably simply because they are "designed" to stay in one place. The stand-alone units (WD4050) are about $10 less at Home Depot, but I have yet to find a store that stocks them. They seem to still be available online though. I called Ridgid (1.800.4RIDGID) and was told that the 1 7/8" to 1 1/4" adaptors are not included with any models anymore, and furthermore the adaptors have been discontinued altogether. Apparently Ridgid makes a 1 1/4" hose that can be used with either model if you want to order one to increase static lift, or want to use 1 1/4" tools you already have.