Simple step IS simple.

Evenflo Simple Step is a pressure mounted gate. (Therefore not suitable for top of stairs) It stands 30" tall and has a variable width of 29"-39".

Installation is truly simple, however it is nearly impossible to do with only 1 person! The gate comes with an extension piece for the wider doors and with four rods/four discs. If you need the extension piece it easily snaps into place. You put the discs on the rods and slide the rods into the holes on the four corners. Here is where it is nice to have a second person. One person holds the gate where it should be. The second person turns the discs rotating from side to side until the gate is firmly in place. There is a green/red circle that will let you know when it is secure. Green is good. Red means keep going. That's all there is to installation. Since this is a pressure mounted gate, make sure both sides of the doorway/bottom of stairway are sturdy. (We tried to use ours against the railing of the stairs since we didn't have a full wall. After a few weeks we noticed the railway had started to lean out. )
The trickiest part of the gate is figuring out how to go through it! It's easy once you figure it out though. You press in the blue button and at the same time slide the handle away. The gate swings in either direction. And usually a soft nudge is all that is needed to close it again.
The gate itself doesn't hinge at the edge of the doorway. It hings about 6" in and then with the extension piece on the other side, the gate opening is actually only about 17" wide. It's not a big deal unless you are a big person or taking loads of laundry or other large items through the gate frequently.
As this gate is only pressure mounted, it is possible to dislodge it unintentionally. And by that I mean older children playing on it will take it down. Just something to be aware of.