Bethwaite trapeeze or carbon key-hole system; same thing?

Looking to upgrade to a key-hole trapeeze system. What's the difference between Bethwaite and Key-hole (like the carbon-fibe one shown on Murrays). Is Bethwaite the original design (in plastic maybe). I've read that they've had some problems with breaking (plastic).

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Pairajacks
1985 Nacra 5.2
Corvallis Oregon
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My understanding is that Bethwaite designed the keyhole system after several (6-7) drownings when trapped under a turtled boat perhaps because of lines snagging the trapeze hook. The original ones I bought were plastic hooks which did break & Murrays then switched to the all carbon hooks. I simply carbon fibered my plastic hooks & continued using them as kids weight was under 140 #'s. Pete