Foregrips come in different types and sizes, from plastic to metal, angled grips or vertical grips, in black or Dark Earth.
Choosing a Foregrip is really based on personal taste and what you like best. Some people prefer an angled grip because they are more ergonomic, others prefer a Vertical Grip. Make sure to choose a Foregrip that matches the system on your handguard. Think of Picatinny, Keymod or M-Lok systems.