There are two ways to get inside the hyperbaric chamber. Depending on if someone ability to get in and out by themselves the ones that are easier to get in on the top or from the side needs to be decided. It is not just about just getting in, zipping yourself up when the zipper is on the side can really tired out the top shoulder if you have to massage the rubber seals and zippers to get the hyperbaric chamber to close right.
On some of the hyperbaric chambers, you can't turn on the side because of the valve locations. If you try to turn it on the side the valves, especially if they are not metal valves can get messed up and you can't run it right when the valves are on the bottom.
For immobile people, it is much easier to get in from the side and for mobile people, it is easier to get in on the top of the chamber.
Straps make the chamber much harder to get, especially if getting in alone, and can be even harder for immobile people who cannot bend and reach the last strap.
Note: The models with the belts, they are are the side entry ones. Most people that cannot afford the high end commercial models usually get the strap type. Most people that are coming out of a wheel chair prefer the side entry also. I recommend trying the strap model first so you know if you like it. The distributors I work with will let you have a 2 week money back guarantee so that if you don't want to keep it after buying it you can return it. There is always someone that wants to buy one of these returns at a discount, so they never give you a hard time with returns. There are actually people on a wait list just waiting for someone to return one so they can get a bigger discount.