I have been searching everywhere for a SM-950 steam diffuser and cannot find one anywhere. I have a SteaMist generator that is about 10 years old. I replace the shield every couple of years since it does seem to break quite easily but I have grand children that like to come over and take a grown -up steam bath which is fine by me, (well monitored of course); but i am always concerned with them getting too close to the steamhead and getting burned by the hot steam. You are my last resort and I don't want to deny the kids their time in the steam room.

Glad to hear you have safety in mind.  Steamist discontinued the SM-950 diffuser as they came out with a new style of steam head that has a self diffuser feature.
The choice you have is to purchase our robust teak and stainless steel guard and it will be you last purchase you make on a diffuser as it should last forever.

Check out AccuRate Steam Guard

Oh no. I don't like that at all. Isn't there some other alternative?

Ok.  There may be another option but first it is importmant to know the size of your current steam head.  10 years ago if could be either 1/2" or 3/4".

it looks pretty big but it has a reducer inside the head the pipe is 1/2"

What is your wall material?  acrylic, fiberglass, ceramic tile, marble, etc.

It is ceramic tile

Ok.  Assuming that your steam head removes very easily since you stated you've had to replace the diffuser many times, then there is an alternate to the steam guard I first suggested.  It is important that your head removes easily as we do not want to create a leak by loosening a pipe in the wall.
You can look to replacing your old steam head with the new Steamist 3199 steam head that is self diffusing.  This new steam head is 3/4 inch NPT and if you have a 1/2 inch steam line, then you will need a bushing for the size transition.

The cost for a new steam head will be close to the steam guard I suggested, so you may wish to err on the side of the easiest solution and purchase the steam guard.

Here is the steam head info Steam Head 3199

Check out Bushing

Thank you so much. This looks like just what the doctor ordered.