The part that keeps it standing.

The one it shipped with. Little Tikes: "Only the blower supplied should be used for inflation." Action Air and Bounceland allow the supplied blower or a replacement the maker specifies, and Sportspower and HeroKiddo say the same in their own words. The blower is matched to the unit, so the numbers that count are the ones on your blower's label.

For a sense of scale, here is what's printed for the units on GoJumps, smallest blower first:

Bounceland's castles ship with a UL blower on a 25 foot cord and a GFCI plug, with no rating printed; the replacement Bounceland sells is rated 782 to 816 watts. Action Air prints no rating. WELLFUNTIME's water park listing names a 520 watt blower in one place and 640 in another, so it stays off the table.

Roughly, then: most units up to the 12 by 9 classics run on 280 to 450 watts, the bigger castles, water parks and courses on 480 to 750, and the heaviest on 1,100 watts or a 1.5 horsepower motor. A bigger blower isn't an upgrade. It's another unit's blower.

Not by any manual we read. The only two options they allow are the supplied blower and the maker's own replacement, and a leaf blower is neither. Little Tikes also says not to run its blower through a solid-state speed control. If yours fails mid-season, the fix is a replacement from the maker, not whatever is in the garage.

Pump-up units work differently. The Intex Jump-O-Lene fills once with an air pump and holds its air, and Intex warns against over-inflating it or using a high-pressure compressor, since either may cause seam leaks.

Little Tikes prints it under "Electrocution Hazard": do not use extension cords. Action Air, Sportspower and HeroKiddo agree, and Blast Zone won't recommend one. Pogo's guide argues with itself, asking for a 12 gauge cord in one place and ruling out extension cords in another.

So the blower's own cord decides where the unit can sit. Bounceland and Action Air list 25 feet of it, WELLFUNTIME 13 and Easyair 12.5, and Blast Zone offers 75 foot cords as an option on most of its units. Measure from your outdoor outlet before you pick the spot, not after the stakes are in.

The outlet matters too. GFCI (ground fault) protection is required by Little Tikes, Action Air, Bounceland and Sportspower, and several of these blowers carry it in the plug. If one won't start, Little Tikes says to press the reset button on the plug.

For the length of the party. Every manual we read says the blower stays on while anyone is inside, and none puts an hour limit on a session. What they rule out is leaving it unattended (Little Tikes, Sportspower) or inflated overnight (Action Air, Bounceland).

Blast Zone builds overheating protection into its blowers: if it trips, the blower shuts down for about two hours before it restarts. Blast Zone suggests keeping the blower in the shade when you can, and the manuals want the intake kept clear.

Little Tikes wants the blower somewhere it won't suck in dirt or leaves, and Sportspower adds sand and small stones to that list, with a reminder in each to check the intake during use. Stake it down too (Little Tikes, Bounceland and HeroKiddo require it), since Sportspower warns that a gust can lift it.

Then keep it out of small hands. Little Tikes doesn't recommend its blower be run by anyone under 8, Bounceland says 16 and Action Air 18. On its water park, Little Tikes also asks that children stay off the side where the blower attaches.

Some listings call their blowers waterproof, Bounceland's and WELLFUNTIME's among them. The manuals still treat water as the enemy. Little Tikes says never to leave the blower out in the rain and to keep the cord away from water and damp ground. Action Air says that if water reaches the blower, unplug it and don't run it again until it's completely dry, and Pogo says much the same.

With a water slide, set the blower well away from the spray. Action Air says to make sure water doesn't spray toward it, and Little Tikes says to move it to dry ground if draining water heads its way. The CPSC adds a broader warning: keep children away from air pumps and generators, especially near standing water.

Of the makers we read, only Blast Zone addresses it: yes, with an appropriately powered generator. The others don't mention one, so ask your unit's maker before planning a party around it, and keep the CPSC's warning about children near generators in mind.

When the party's over, unplug the blower and let the unit fold down. Nothing goes away wet. That rule is in the Little Tikes, Action Air, Sportspower, Pogo and HeroKiddo manuals, and Bounceland's warranty doesn't cover mold or mildew from damp storage. Pogo's fix for a damp unit is to dry it the same day by blowing air through it, and Little Tikes says a water park can take two hours or more to dry. The blower itself goes indoors, somewhere dry.