This 'short' 2x20 double row header is great for a slim connection to your Raspberry Pi model A+ or B+, it's basically the through-hole version of the SMT GPIO Header for Raspberry Pi HAT - 2x20 Short Female Header.
This header is for super-slim through-hole designs. It's a custom-made, 2x20 short female header that can be used to plug a Raspberry Pi HAT onto a B+, A+, or Pi 2. It's easier to use than the SMT type headers, but it's great for the slickest, slimmest fit, that a through-hole Raspberry Pi header has to offer.
Specifications:
Dimensions: 51mm x 8mm x 5mm / 2.0" x 0.3" x 0.2"
Rows: 2
Pins per row: 20
Pin Length: 3mm
Pin Spacing: 2.54mm / 0.1"
Pin Thickness: 0.6mm / 0.02"
Weight: 2g