Thermal fuses are actually pretty small, this one (which is pretty representative): http://uk.farnell.com/nte-electronics/nte8065/fuse-thermal-cutoff-10a-250v-a

Thermal fuses are actually pretty small, this one (which is pretty representative): http://uk.farnell.com/nte-electronics/nte8065/fuse-thermal-cutoff-10a-250v-axial/dp/2192420 http://uk.farnell.com/nte-electronics/nte8065/fuse-thermal-c... is about the size of a 1/4W resistor at 12mm long. A fuse isn't too big either, this 0402 fuse: http://uk.farnell.com/te-connectivity-raychem/dp/1843788 http://uk.farnell.com/te-connectivity-raychem/dp/1843788 is rated at 4A and is only 1mm long! The real thing for size is the transformer and other magnetics, which decrease with frequency, hence why this uses VHF frequencies. Output filters can also be made smaller at higher frequencies, and Ken Shirriff's iPhone charger teardown above shows a small ferrite ring _inside_ the charger case for high frequencies. UL Approval is probably under on the "Production Timeline" (2/3rds down) under "Submit for initial regulatory certification (4 months)", which is set to begin now (Apr-May). As for the wire thickness, it doesn't seem that much thinner than my Macbook Charger, which is also 65W. The production timeline on the kickstarter leaves them time to change to a thicker one. The big question of course, is the feasibility of the VHF AC-DC conversion. FINsix have a paper (http://finsix.com/assets/files/FINsix_Tech.pdf http://finsix.com/assets/files/FINsix_Tech.pdf) but its not very long or detailed, and I don't know enough to criticise it if it was.