This 1/4 lbs. spool is just the right amount, not too much a like those little. 0.031 inch diameter 60/40 no clean rosin core. Good for all through-hole soldering and some larger SMT soldering especially when used with wick. Alpha fry very fine electrical rosin core solder60 percent tin / 40 percent leadFor electrical soldering requiring low melt tempsMelting point 376 degree Fahrenheit4 oz. spool