Adafruit STEMMA QT sensor breakouts (BME280, BNO055/085, VL53, SCD-40, AHT20, SHT40, IMUs, light, magnet, RTC…) — dimension sheet Source: Xem Studio, https://xemstudio.com/objects/adafruit-stemma-qt-breakouts/ (CC BY 4.0) Basis: Adafruit CAD (MIT); most STEMMA QT breakouts are 25.4 × 17.8 mm (1.0 × 0.7 in) with two Ø2.5 mm holes 20.3 mm apart, JST SH 4-pin connectors on both short ends Catalog version: 2026-10-20 Sizes: see table below - The common STEMMA QT breakout: 25.4 × 17.8 mm, two Ø2.5 mm holes on 20.3 mm centres (0.8 in) along the long axis, 2.54 mm header row on one long edge, JST SH 1.0 mm 4-pin at each end; 1.6 mm PCB, 4–6 mm tall with connectors. - Larger ones: SCD-40 (33 × 25.4), MLX90640 thermal camera (25.4 × 25.4), PMSA003I air quality adapter (38 × 25), PCA9548 mux (33 × 17.8). - Cable: STEMMA QT / Qwiic JST SH cables need 8 mm of clearance beyond the connector for the plug and strain relief. product bbox_l_mm bbox_w_mm bbox_h_mm 2652 Adafruit BME280 25.4 17.8 4.5 4646 BNO055 Stemma 25.4 20.3 4.5 4754 BNO085 STEMMA QT 25.4 22.9 4.5 5396 VL53L4CD Sensor 25.4 17.8 4.5 5187 SCD-40 C02 Sensor 25.4 22.9 7.9 4566 AHT20 Sensor 25.4 17.8 4.5 4885 SHT40 Sensor 25.4 17.8 4.5 2809 LIS3DH 25.4 17.8 4.5 4502 6DoF IMU 25.4 17.8 4.5 5378 VEML7700 Lux Sensor 25.4 17.8 4.5 3595 APDS9960 Sensor 25.4 17.8 4.5 5188 DS3231 RTC 25.4 17.8 7.7 904 INA219 Stemma 25.4 20.3 4.5 5626 PCA9548 Stemma 40.6 20.3 4.5 1085 ADS1115 ADC 25.4 17.8 4.5 5346 MCP23017 Expander 43.2 17.8 4.5 6357 AS5600 Magnetic Sensor 25.4 17.8 4.5 4698 AS7341 Light Color Sensor 25.4 17.8 4.5 4469 MLX90640 Stemma 25.4 17.8 11.7 4632 PMSA003I 50.8 35.6 14.0 4097 ADXL343 Accelerometer 25.4 17.8 4.5 4494 DPS310 Sensor 25.4 17.8 4.5 4816 BMP390 QT 25.4 17.8 4.5 3660 BME680 25.4 17.8 4.5 5046 BME688 Sensor 25.4 17.8 4.5 4867 SCD-30 C02 Sensor 50.8 25.4 11.5 4161 VCNL4040 Sensor 25.4 17.8 4.5 4022 Wide-Range Triple-axis Magnetometer MLX90393 22.9 19.1 3.0 3967 VL5SL1X TOF Sensor 25.4 17.8 4.5 4415 Mini GPS PA1010D 25.4 25.4 12.0 5579 MMC5603 Magnetometer 25.4 17.8 4.5 5832 INA228 STEMMA QT 25.4 20.3 12.1 6062 INA3221 Power Monitor 38.4 22.9 11.9 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, 33 parts): https://xemstudio.com/files/adafruit/adafruit-stemma-qt-breakouts/index.json API: https://xemstudio.com/api/geometry?object=adafruit-stemma-qt-breakouts