The Pneumatic Boots provide a couple of useful inbuilt features, along with a couple of very interesting upgrades...

• The boots provide inbuilt fall protection - no upgrade needed - at a modest air cost (the amount of air used is proportional to the fall damage which would have been taken).
• The boots provide 1-block step assist for free - no air cost.  Note that this is step assist, not auto-jump, and it's a toggleable feature (step assist is not to every player's taste).

[prefix{l}]Dispenser Upgrade[prefix{}]
By adding one or more Dispenser Upgrades to the boots, you gain the ability to execute a [prefix{o}]pneumatic kick [prefix{}].  This will do moderate damage to entities (and not just living entities!), but also inflict heavy knockback, at a modest air cost.  Up to 4 Dispenser Upgrades can be installed.

[prefix{l}]Jet Boots Upgrade[prefix{}]
If you've ever wanted to soar through the air without a care in the world (except how much pressure you have left), the Jet Boots upgrade is for you.  You can add up to 10 Jet Boots upgrades for progressively faster flight, and heavier air usage.

The Jet Boots are a [prefix{o}]heavy [prefix{}] user of pressure; it's strongly recommended to add multiple volume upgrades to your boots (and chestplate, with Charging Upgrades). Use of an [link{block/aerial_interface}]Aerial Interface[link{}] is also advised when possible.  You will also need a good charging infrastructure at your base.