I have used these in many racks with both M5 and M6 screws. These ARE compatible with both M5 and M6 screws because adaptors are provided for M5 screws.
As noted by another reviewer the can get mis-shapen if you are not careful, but this has only been a cosmetic problem for me.
As for isolation, they have worked every time for me (tested). I have not had trouble keeping the faceplates isolated. Important: when testing for isolation/continuity, remember to unplug all of the power cables from power distribution unit to rack devices. Otherwise the meter will indicate continuity, since the devices are joined through the PE/ECC conductor of each piece of gear (and this is how it must be for safety - NEVER cut a ground/PE/ECC conductor.
its only true purpose is to prevent against rack rash, it does not isolate equipment from each other, rather it isolates the rack equipment from the rack rails, so if 1 unit is causing hum this will transfer along each unit as their faceplates arent isolated
the screws dont fit my adam hall rack or gator case, it comes with a soft adapter for smaller screws
you have to cut the pieces out of their molds which isnt too difficult, but takes some accuracy to get them looking smooth with no bits sticking out.
the rubber/plastic warps/goes out of shape and shift position before you have the screws tightened, its difficult to gauge when its tight enough, when it feels tight your left with a misshapen piece
I dont normally right reviews straight after using a product but was so let down by these that I felt the need to write a review. some old bicycle inner tube would work better, or 2 plastic washers per screw would achieve the same
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