First off the label says it it non-toxic, which is kinda strange considering that it also says not to allow it to contact skin, eyes, painted surfaces and brake systems. I guess what they mean is that it can cause serious injury but wont kill you. Anyway the good stuff:Claims to work on:Engine leaksTransmission leaksPower steering leaksRack and pinion leaks& any other fluid systemException: do not use in brake systems.Pros:Does not appear to mush out (over-soften) rubber seals/rings when used full strength (undiluted). Seals seem to retain their elasticity and tensile strength (great).Not much odor, clear and easy to handle.Cheap for what it claims it does.Cons:Tiny bottle 8 oz.Observations:So far, I have not yet seen where the rubber seals/rings increase in size (expand)when soaked overnight at full strength (this was a bit odd).Cheap enough to be used for testing purposes. Based on limited testing I can only say that it seems that it would only seal very tiny leaks, since the rubber seals dont appear to swell (within human perception).I will update when further info becomes available (shortly). I am currently testing on a few items: transmission dipstick seal, civic top cover bolt seals, AC coupler o-ring, distributor seal, suspension bushing (front and back), radiator cap seal (watching this one closely).I will also change the rating - i hope it will do well.Update on Nov 10, 2012Transmission dipstick seal - works great, its now firmly in place - was very loose before using.Engine Oil dipstick seal  - works great, its now super firm in placeNote: Both dipstick seals took a whole week to swell and notice the difference.Civic top cover bolt seals - just applied some today, have to wait on results.AC coupler o-ring - no visible signs yet. Will have to use on live AC system totest. Windshield wiper rubber - Not recommended, rubber becomes too sticky and uneven - does not  clean debris well after use.Update to Jan 26, 2013:  Used it to stop a small power steering. It did make some difference to slow the leak even more. It did not stop the top cover bolt leak, nor the small transmission & engine leak (Only used a little in all three).Radiator cap seems marginally more prone to leaking after the fact. So I guess this product works best under certain "ideal" conditions. I would still buy itfor specialist applications due to its cheap cost.