I have 3 types of ESP32 hardware available around:

• The HelTex WIFI_Kit_32, an ESP32 with Wifi/BT and an OLED screen (I2C).
• IDF config: CPU freq 240 MHz, XTAL 26 MHz, SPI flash 4 MB (no RAM), internal SRAM 520 kB.
• Features: USB serial CP2101, Wifi, BT, OLED (cannot be removed), battery plug.
• Does NOT have: sdcard. No SPIRAM.
• The ESP32-CAM, an ESP32 with Wifi/BT, sdcard, camera.
• IDF config: CPU freq 240 MHz, XTAL 40 Mhz, SPIRAM 4MB (on SPI bus), SPI flash 4 MB (no RAM), internal SRAM 520 kB.
• Features: Wifi, BT, OV2640, sdcard (shared with onboard LED!).
• Does NOT have: USB serial, no OLED. Requires FTDI for access/program
• The ESP-32S …Should have similar specs to the HelTek Wifi Kit 32, without the OLED or sdcard or camera. It has a micro USB and a CP2102 UART. The ESP-WROOM-32 is listed as having a XTAL 40 Mhz in the Espressif docs.
• Features: USB serial (CP2102), Wifi, BT.
• Does NOT have: No sdcard. No OLED. No SPIRAM.