can i use it with a hollis sms 100? for put one cylinder in my back?
HYUNWOO K Here is the answer from Hollisgear I got last year.
The SMS100 was designed with primary application of sidemount. Mounting a tank to the rear of the harness will be secure, however when compared to a traditional BCD slightly loose. It is only recommended using the supplied cam bands, we do not recommend using a single tank adapter in this case as the support will be much less.
If your goal is to use a tank and the tank feels wobbly on the rear, have you considered diving one tank on the side? This is very common as well.