Adafruit Solder Wire - 60/40 Rosin Core - 0.5mm/0.02" diameter - 50 grams

If you want to make a kit you'll need some solder. This 0.1 lb (about 50 grams) spool is a good amount, not too much like 1 lb spools and not too little like those little 'pocket clip' vials.

This spool of solder contains approximately 0.6mm / 0.02" diameter with a lead-tin formulation. This is not lead-free solder, so it's not suitable for lead-free/RoHS shops. However, for kit builders, it's a joy to use, much easier than lead-free, and great for beginners.

For flux, it contains a 'no clean' rosin core. This diameter solder is best for any SMT/fine-pitch work as it allows you to deposit small amounts of solder. This is "60/40" leaded solder with 37% Pb (Lead), 63% Sn (Tin), and trace amounts of Ag (Silver), Cu (Copper). Even though this is not truly 60/40, it is close enough for us to consider it a replacement.