The phrase "a small window at" is correct and usable in written English.
It can be used to describe a specific location or feature, often in relation to a physical space or a metaphorical context.
Example: "There was a small window at the end of the hallway that let in a soft glow of light."
Alternatives: "a tiny opening at" or "a narrow aperture at".
But there was apparently a small window at the top of the module.
Inmates take turns looking through a small window at the far end of the room.
Afterward, he and his colleagues took turns peering out a small window at the mushroom cloud and the ground damage.
Light snuck through a small window at the apex of the round roof, but most of the healers inside wore headlamps as they offered hot tea and herbal remedies to the steady stream of visitors ducking through the door.
If you don't find anything you like, you are given a small window at the start of the month to decline to participate that month.
The thin hand with the red tip notes the day of the month while a small window at twelve o'clock notes the month and day of week.
He put in new walls, paneling, cheap floor tiles and a small window frame at the back of the room, to make it look as if he's peering into his neighbor's apartment.
The WBV employs a small window centered at the current coefficient position.
The steady-state gating properties are shown in Fig. S3 A, which shows a small window current at −45 mV, close to the late phase of mouse SAN AP diastolic depolarization.
A small window was made at the pointed end of the recipient egg, and 2 µl (containing approximately 3,000 cells) was injected into the upper portion of the dorsal aorta of the stage 13 WL embryo (50 h of incubation) using a micropipette.
To make it possible for PLINK 1.9 to handle the huge datasets that benefit the most from these speed improvements, the program core no longer keeps the main genomic data matrix in memory; instead, most of its functions only load data for a single variant, or a small window of variants, at a time.
