A Level Ball is a somewhat different ball which becomes more effective when used on Pokémon at a lower level than the lead Pokémon. These balls can be extremely effective on legendaries as a substitute for Ultra Balls or Master Balls if you have a lvl 100 and the legendary is down to approx. 10% health. Note: The system applies to the pokemon currently in the battle, not the others in your team.
To craft a Level Ball Lid, you'll need 1 yellow cooked Apricorn, 1 red cooked Apricorn and 1 black cooked Apricorn. Place the 3 cooked Apricorns in a row horizontally in a crafting bench in that order, obtain the disc, and then use the anvil to make it into the Level Ball lid.