Because someone said you need 600 joules, that proves you need 600 joules. It is called hearsay or junk science reasoning.
Add facts. Destructive surges can be hundreds of thousands of joules. Surges that are hundreds of joules will even be converted by a Mac into rock stable, low DC voltages to safely power its semiconductors. IOW best protection at a Mac is already inside the Mac.
Your concern is a rare and destructive transient that can overwhelm protection inside a Mac and all other household appliances. * If anything needs that protection, then everything needs that protection.* Protection is always about where hundreds of thousands of joules harmlessly dissipate. Always as was true even 100 years ago. The science it that well proven.
Most only know because some fancy citation with colorful pictures said so. Also called propaganda. It targets the naive who never demand supporting facts and especially numbers.
As Ben Franklin demonstrated, lightning seeks earth ground. If permitted anywhere inside a house, then lightning goes hunting for earth destructively via appliances. Nothing stops (blocks) lightning. But that is what a 600 joules protector would do. Protection means lightning is connected to earth BEFORE entering a building.
TV cable already has best protection. A hardwire connects low impedance (ie less than 10 feet) to an earth ground electrode. A surge earthed before entering need not go hunting inside. Telephone cannot connect directly to earth and still provide service. So a 'whole house' protector (installed for free by the telco) connects to earth - doing what that hardwire does better. Cable, telephone, and satellite dish are required to have properly installed protection. Unfortunately many electricians and installers never learn this stuff. Inspect your protection - every a low impedance (ie less than 10 foot) connection to single point earth ground.
AC electric is not required to have protection. You must install it. Informed homeowners earth a 'whole house' protector; often in a breaker box or behind the meter. Lightning can be 20,000 amps. So a minimal 'whole house' protector is 50,000 amps. Since no protector must fail during any surge. Note: numbers are provided to say what and why.
Spend $20 or $85 per protected appliance for that near zero (600 joule) protector. Or spend about $1 per protected appliance for protection designed for real surges. Your choice.
All of this is layman simple. But it is new. It requires unlearning urban myths (that others have posted). So it will require multiple rereads. And will probably generate plenty of questions. Best answer is a simple solution that costs tens or 100 times less money.
Bottom line in any protector recommendation: where are hundreds of thousands of joules harmlessly absorbed? Anything that does not answer that question is best suspect as a scam. Plenty of scams are recommended only because some citation, salesman, or stranger said it was true - without any numbers? Effective protection does what Ben Franklin demonstrated in 1752. Only solution found in facilities that must suffer direct lightning strikes without damage. And a least expensive solution provided by other companies known for integrity.
That near zero 600 joules protector has no earth ground. Protection is about where hundreds of thousands of joules dissipate. A protector is only as effective as its earth ground.
