I have a Stealth Hawk but I'll be damned if I can tell you exactly what MP45 is or is made out of. Here is the info Jerry Busse posted awhile back---
The Stealth Hawks were introduced in 1992 and were discontinued due to our inability to get anymore of the elusive MP45 material. It was manufactured for us by a small plastics maker who specialized in "hand lay-up" plastics. Each sheet was individually made by hand. The one polymer that was used dates back quite a while and was considered to be out of date. Only one factory still made it and the EPA whacked them. Apparently the fumes that were emitted during manufacture were considered to be carcinogenic. The cost of upgrading the facility to fall within EPA guidelines would have been far too expensive to afford. They decided to shut the facility down and with it, went one of the primary ingredients of MP45. Shomertec bought nearly all remaining stores of these awesome blades. We did keep some of the material for customs including a custom sword that was made approx. three years ago. There have been some custom pieces out of this material including a BAT Stealth Hawk. . . very cool piece. They sold for $225.00.
These do not carry the standard Busse Guarantee against any and all Major damage. It's that whole plastic material thing. However, we do offer a free replacement when the knife is used to save a life. We have honored this more than several times. These knives have been there for many law enforcement and military personnel when they needed them most.
I wouldn't recommend it for scuba applications if the intent is to cut monofilament line. It will more likely hang up in the teeth rather than be cut. However, for light prying and digging it can be very effective.
It was originally designed for bomb squads who were worried about magnetism and spark generation. It was quickly adopted by many undercover "buy and bust" teams who were being run down with metal detectors by the drug dealers who were in search of guns and or badges. The Stealth Hawk soon gained a reputation as the best choice as the last line of defense against the bad guys. At 2.5 Ounces it could be easily carried and concealed.
In performance tests, we were able to pound the Stealth Hawk through car doors and 55 gal. steel drums. We pounded it through 6"x6" wooden beams and cut or tore through 17 pieces of 1/2" hemp rope. We then flexed it in a vise up to 20 degrees and it returned to true. No other plastic knife could come close to doing any one of these tests . . . . Awesome performance! Shomertec has some left, but they have been blowing off of the shelf since they were featured in the Los Angeles Times article on October 18th.
They are priced at $137.00. A Kydex sheath with no metallic fasteners is extra.