Multicore Solder

[gridds]

Just a general solder question. I found a seller for Multicore solder - 63/37 (tin/lead) 0.38mm 370 Flux 5 Core.

However I can't seem to find any information on the web for 370 63/37 0.38mm, I found 60/40 0.38mm. Would this be a safe buy? Packaging looks legit.
Unsure about posting the AD, it is listed on eBay, seller has received it from HGR Industrial Surplus.

[Audioguru]

63/37 solder hardens suddenly when cooling and always makes a good solder joint but 60/40 solder goes though a "plastic phase" which causes a poor solder joint if the wires move while the solder is cooling.
Why buy a cheap maybe Chinese unknown solder from ebay? Instead buy a Name-Brand solder from a REAL local electronics distributor. 

[Gregg]

Google genuine Multicore solder and look at the pictures, then compare to the picture on FleaBay.  If they can't even copy the label well, how much effort do you suppose they put into the solder?