How is Kaila Airtrim model different from general Kaila BC?
Is there any functional difference?
MARK P G
The airtrim system takes the place of a more conventional inflator hose and deflation system. The power inflator hose from your regulator connects to the the bc at a point above your left hip where the controls for the airtrim system are located. There are two "buttons" on the airtrim the one on the front slowly lets air out of the bc for decent, the one on top of the bc is the power inflator to ascend. The controls are very intuitive and allow you to fine tune your buoyancy extremely well. The two slight draw backs to this system are that it lets air out of the bc very slowly, so that for the initial descent, I find it easier to pull the dump valve lanyard to let air out. The other is that the oral inflator is a hose that coils up into one of the side pockets of the bc, rendering that pocket more or less unusable for anything else. These are two very minor "grips". I would recommend the airtrim system as it make achieving neutral buoyancy during the dive very easy. I hope this helps.
With the "regular" Kaila BC you adjust your buoyancy using a hose - with the Airtrim style you adjust buoyancy with 2 buttons (red/grey) near/at your waist. This makes it possible to adjust your buoyancy virtually in any position. I have owned 2 different Mares Airtrim type BC's (one being the Kaila AT) and I will never own anything else. My husband has the Mares dragon airtrim - the airtrim style is great. It is very easy to get used to and very comfortable - you barely have to move to make adjustments and no hose to get in the way.
The Kaila AT is so comfortable, lots of padding near the neck and back, the back padding can be adjusted, if your tank is hitting your lower back you can fold the padding down. I wasnt sure about sizing so I will give my size info and maybe that can help someone. I am 5'7" and weigh 154 (clothing size M, 6/8) and I have the size small and it couldn't be more perfect. I have done about 20 dives with this BC and my only complaint is the pockets could be easier to get in and out of in the water. Otherwise I love it!