Your opening reads 38 in on one side and 41-1/2 in on the other, because 1985 framing settled. Pick the mechanism that forgives it. A brushed gold pivot rides sliding jamb tracks, a frameless bifold folds instead of arcing into the toilet, and a double-pivot pair opens a 41-1/8 in walk-in. Every shower door ships 1/4 in (6mm) certified glass, a 304 stainless handle, and full-coverage sealing strips.
Measure a shower opening before the tile goes on and you spend 3/8 in of wall-profile play before the crate lands on your driveway. Chase a 1/4 in of wall lean with a fixed-frame door and you re-order the glass instead of installing it. Rodkedc puts the adjustment in the hardware, so you take up that lean on site in an afternoon. Push a 6mm panel with your palm and it flexes where a 10mm slab stays dead solid, which is the trade you make.
Pull the telescopic tracks out and you place the frame anywhere across 4 in of width, wherever the wall actually sits. Press the wall profile over another 3/8 in per side, and a wall that never sat true stops sending you back to re-order. Look the glass up before you bolt anything: each 1/4 in (6mm) tempered panel prints SGCC, ANSI Z97.1-2015, and CPSC 16 CFR 1201, so you check all three in ten seconds. Hang the 24 in mirror over the vanity months later and the same matte black aluminum frame repeats, so the room reads as one job.
Read the review record before you decide: two doors hold 5.0 stars across 4 verified reviews, a sample small enough that dressing it up would be the first thing worth distrusting. Send back a panel with a manufacturing fault and a replacement ships inside the return window. Photograph glass cracked in transit the day it lands and it gets reshipped rather than disputed.
Match door frame to mirror frame, take up an old wall's lean on site, and hear the 6mm part out loud.
Set the double-pivot door against the 24 in mirror on the same wall and the rounded matte black aluminum profile matches edge for edge. Buy the door in March, add the mirror in June, and a visitor still reads them as one purchase.
Spell a standard out by its number on the spec block and it takes four lines where one adjective would do. Type any one of them into a search bar and you have your answer in ten seconds, without emailing anyone for a datasheet.
Slide the track through its 4 in of travel on install day and that mechanism costs more to build than a fixed panel. Hand the same frame to a 38 in alcove and a 42 in one, and neither needs a separate part number.
A 6mm door sits a tier below the 10mm frameless slabs, and hiding that would surface the first time you push on the panel. Choose the 10mm tier when you want a 36 in wide panel dead solid under your palm; choose this one when the wall is out of square and the schedule is short.