these are only for certified jumpers who have experience in this type of
parachute. However, it also should be noted that square parachutes do not
function like round or conical parachutes, they don't open reliably unless
you are in a stable position, something you likely will not be in
immediately after a bail out and may never be in if you're not an
experienced jumper, more likely you will exit and emergency bail out
tumbling and even with experience you may be disabled and unable to enter
into a proper PLF position for deployment.

That used to be true ... a looooong time ago ... but square (ram air)
parachutes became much more reliable that round ones within a few
years after they were invented. (Round parachutes inherently want to
be in a closed configuration. Ram-airs want to be open. Emergency ram-
air parachutes are far more reliable than round ones, in any
deployment position, which is why round ones are so rare among
skydivers today, as emergency parachutes.)

Modern emergency ram-airs like the P-124 are every bit as dependable
as the rounds, and they are (by design) docile, forgiving, pretty much
idiot proof, and you can pretty much land them where you want, clear
of power lines, houses, lakes, freeways, and Lennie.

2NO
4300 ram-air jumps, zero deployment malfunctions