Adafruit QT Py, ItsyBitsy, Trinket, GEMMA and Trinkey boards — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/adafruit-qt-py-itsybitsy-trinket/  (CC BY 4.0)
Basis: Adafruit CAD (MIT): QT Py 21.8 × 17.8 mm (0.86 × 0.7 in), ItsyBitsy 36 × 18 mm (1.4 × 0.7 in), Trinket M0 27 × 15.3 mm, GEMMA M0 Ø27.9 mm
Catalog version: 2026-10-20

Sizes: see table below
- QT Py (every variant: SAMD21, RP2040, ESP32-S2/S3/C3/PICO): 21.8 × 17.8 mm, USB-C at one end, STEMMA QT JST SH at the other, no mounting holes; cases hold it by the edge with a 0.3 mm lip.
- ItsyBitsy: 36 × 18 mm, 28 pins on 2.54 mm pitch, no holes. Trinket M0: 27 × 15.3 mm with two Ø2.5 holes. GEMMA M0: Ø27.9 mm round with three large sew pads.
- Trinkeys are USB-A plug boards (~34 × 18 mm with the plug); KB2040 is a Pro Micro footprint (33 × 18 mm, 24 pins).

product  bbox_l_mm  bbox_w_mm  bbox_h_mm
4600 QT Py  21.8  17.8  6.3
4900 QTPy RP2040  21.8  17.8  5.9
5426 QT Py ESP32-S3  21.8  17.8  5.9
5395 QT Py ESP32 PICO  21.7  17.8  5.6
5325 QTPy ESP32S2  21.7  17.8  5.9
5405 QTPy ESP32 C3  21.7  17.8  5.9
3800 ItsyBitsy M4  36.0  17.8  4.3
4888 ItsyBitsy RP2040  36.1  17.8  4.3
4481 ItsyBitsy nRF52840  36.2  17.8  5.7
5889 ItsyBitsy ESP32  36.1  17.8  7.4
3500 Trinket M0  27.2  15.2  3.6
3501 GEMMA M0  28.0  27.9  6.4
5302 KB2040  34.2  17.8  4.8
4870 Neo Trinkey  31.7  12.1  3.9
4964 Rotary Trinkey  32.4  30.4  16.5
5020 NeoKey Trinkey  31.6  19.2  16.5
5056 Trinkey QT2040  38.1  19.7  5.5
5953 Pixel Trinkey  40.2  15.2  12.0

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Adafruit (official): Adafruit_CAD_Parts: STEP, Fusion 360 and STL for Adafruit products — STEP, F3D, STL — MIT — https://github.com/adafruit/Adafruit_CAD_Parts

Free files (MIT License (Adafruit_CAD_Parts), Adafruit Industries; STEP + STL, 18 parts): https://xemstudio.com/files/adafruit/adafruit-qt-py-itsybitsy-trinket/index.json
API: https://xemstudio.com/api/geometry?object=adafruit-qt-py-itsybitsy-trinket