。
Good leather lasts for years.
Literal
Good leather [topic-は] many years lasts.
もつ ('to last, keep, hold up') is the intransitive verb for durability — 何年も (many years) as the duration modifier, adverbial without a particle. 何~も is the 'many X' pattern, used to express large unspecified quantities — 何回も (many times), 何度も (over and over), 何人も (lots of people).