I plan on purchasing a 901 adapter from the reo site. I assume that hes tested them on his units for size and such. but I hear you should attach your adapter to the atty and test it before attaching to your Reo, to avoid a possible short. I bought a 901 from Nhaler to use on my silver bullet, and the end was too long and fried my silver bullet. when i sent it in to be repaired, chad was kind enough to shave my adapter to fit my bullet safely. I would advise buying the adapters from the sites where you purchased the unit that you plan to use it on. and still check it before using it.