Usage Tips:Dimensions: 5mm x 51mm x 23mm / 0.2inch x 2inch x 0.9inch Pin Length: 12mm; Pin Spacing: 2.5mm / 0.1inch; Pin Thickness: 0.6mm / 0.02inch It's a Stacking Header for Raspberry Pi A+ Pi Model B+ Pi 2 Pi 3 - 2x20 Extra Tall Stackable Header 2 Spacers. Stack multiple plates, breakouts etc onto your Raspberry Pi with this 2x20 female header. The female header part has total 24mm extra tall: when placed on your Pi, a PCB will clear the Ethernet and USB jacks. Plastic height is 8.5mm, pin length 10.5mm so that when a standard 1.5mm thickness PCB is installed, there will be remaining plenty to plug into. Pins: 2x20 Compatible with Raspberry Pi A+ Pi Model B+ Pi 2 Pi 3 Colour: black Material: PC+metal Package Contents: 4 x pin headers Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.