Extras are optional non-core rental items that you sell (or rent) alongside your core inventory.

e.g. a helmet, pedals, insurance, lights

some folks even use it for more 'abstract' things:

mountain ski pass, shuttle ride, cycling jersey, water bottle

They appear in your online booking alongside your rental items.

Plus they appear in your back office:

You can charge for them or they can be free.

You decide which extras apply to which type of bike.

Please Note:

-  extras do not count towards your inventory count (BRM subscription)

-  however extras do not track your inventory - so you need to have 'an unlimited supply'

See Also

setting up extras 

your extras compatibility matrix - which products can have which extras