# Stackable 0.100″ Female Header with Extra 0.3″ Spacer: 2x20-pin, Straight

**Type:** Product page · **SKU:** POLOLU-2749 · **Brand:** [Pololu](https://core-electronics.com.au/brands/pololu-australia)
**Page:** https://core-electronics.com.au/stackable-0-100-female-header-with-extra-0-3-spacer-2x20-pin-straight.html ([markdown](https://core-electronics.com.au/stackable-0-100-female-header-with-extra-0-3-spacer-2x20-pin-straight.html.md))

This extra-tall stackable 40-pin female header features two rows of 20 pins spaced with a 0.1″ (2.54 mm) pitch. It includes three 0.1″-thick spacers for additional clearance, and the extended pins allow multiple units to be stacked as popularized on Arduino shields. The 2×20 size is notably used on the Raspberry Pi Models A+ and B+, and the extra 0.3″ of height allows for stacked boards to clear all of the components on the Raspberry Pi B+.

## Pricing

- **Price:** $11.10 (inc GST) — $10.09 AUD, exc GST
- **Quantity discounts:** 10+ $9.69 (exc GST) · 25+ $9.38 (exc GST)

## Availability & dispatch

- In stock, ships same business day if ordered before 2PM (Australia/Sydney).
- We can dispatch 2 today, and up to 200 more in 4–7 days.

## Description

This stackable 40-pin female header features two rows of 20 pins spaced with a standard 0.1" (2.54 mm) pitch; this spacing is the same as on most [solderless breadboards](https://core-electronics.com.au/prototyping/breadboards.html) and matches [0.1" male header strips](https://core-electronics.com.au/0-100-2-54-mm-breakaway-male-header-2x40-pin-straight.html). The extended pins allow multiple units to be stacked as popularized on Arduino shields, enabling removable daughter boards that can access pins without blocking them. The 2×20 size is notably used on the [Raspberry Pi Model A+](https://core-electronics.com.au/catalog/product/view/sku/POLOLU-2760) and Model B+ as well as the Raspberry Pi 2 Model B, Raspberry Pi 3 Model B, and [Raspberry Pi 3 Model B+](https://core-electronics.com.au/catalog/product/view/sku/POLOLU-2797), and its height matches Pololu's [18.6 mm M2.5 standoffs for Raspberry Pi](https://core-electronics.com.au/aluminum-standoff-for-raspberry-pi-18-6mm-length-6mm-m2-5-thread-m-f-4-pack.html).

| \| [![](https://core-electronics.com.au/attachments/localcontent/0J5967_17523805e48.jpg)](https://core-electronics.com.au/attachments/localcontent/0J5967_2052433a9c5.jpg) \| \|---\| | \| [![](https://core-electronics.com.au/attachments/localcontent/0J5968_13966034f91.jpg)](https://core-electronics.com.au/attachments/localcontent/0J5968_142456bfcdc.jpg) \| \|---\|---\| |
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This header includes three 0.1"-thick spacers, which gives it the necessary height to clear everything all the components on the Raspberry Pi Model B+ or the Raspberry Pi 2 Model B. The locations of these spacers can be adjusted if so desired to provide more clearance, or they can be removed to provide less clearance:

| [![](https://core-electronics.com.au/attachments/localcontent/0J5969_226560836d3.jpg)](https://core-electronics.com.au/attachments/localcontent/0J5969_1434402eade.jpg) |
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| The spacers can be adjusted on the Stackable 0.100" Female Header with Extra 0.3" Spacer: 2×20-pin, Straight. |

Pololu also carry a [shorter 2×20 stackable female header](https://core-electronics.com.au/stackable-0-100-female-header-2x20-pin-straight.html) (with no spacers) and a standard (non-stackable) [2×20 female header](https://core-electronics.com.au/0-100-2-54-mm-female-header-2x20-pin-straight.html).

**Dimensions**

| ![](https://core-electronics.com.au/attachments/localcontent/0J5971_57635ad98ed.jpg) |
|---|
| Dimensions (in mm) of straight stackable 0.100" female headers with extra spacers. |

The dimensions in the above diagram are: **A = 48.3 mm**, **B = 51.3 mm**, **H = 16.1 mm**, and **P = 7.1 mm**.

**People often buy this product together with:**

| [![0.100" (2.54 mm) Female Header: 2x20-Pin, Straight](https://core-electronics.com.au/attachments/localcontent/0J5996_2940251c81.jpg)](https://core-electronics.com.au/0-100-2-54-mm-female-header-2x20-pin-straight.html) | [0.100" (2.54 mm) Female Header: 2x20-Pin, Straight](https://core-electronics.com.au/0-100-2-54-mm-female-header-2x20-pin-straight.html) |
|---|---|

| [![Aluminum Standoff for Raspberry Pi: 11mm Length, 6mm M2.5 Thread, M-F (4-Pack)](https://core-electronics.com.au/attachments/localcontent/0J7093_3353f85492.jpg)](https://core-electronics.com.au/aluminum-standoff-for-raspberry-pi-11mm-length-6mm-m2-5-thread-m-f-4-pack.html) | [Aluminum Standoff for Raspberry Pi: 11mm Length, 6mm M2.5 Thread, M-F (4-Pack)](https://core-electronics.com.au/aluminum-standoff-for-raspberry-pi-11mm-length-6mm-m2-5-thread-m-f-4-pack.html) |
|---|---|

| [![Aluminum Standoff for Raspberry Pi: 18.6mm Length, 6mm M2.5 Thread, M-F (4-Pack)](https://core-electronics.com.au/attachments/localcontent/0J7096_2719ffb75b.jpg)](https://core-electronics.com.au/aluminum-standoff-for-raspberry-pi-18-6mm-length-6mm-m2-5-thread-m-f-4-pack.html) | [Aluminum Standoff for Raspberry Pi: 18.6mm Length, 6mm M2.5 Thread, M-F (4-Pack)](https://core-electronics.com.au/aluminum-standoff-for-raspberry-pi-18-6mm-length-6mm-m2-5-thread-m-f-4-pack.html) |
|---|---|

**Dimensions**

 | Pins: | 2 x 20 |
|---|---|
| Spacing: | 0.100 in |
| Weight: | 7.0 g |

**General specifications**

 | Gender: | male-female |
|---|---|
| Pin type: | straight, stackable |
| Current rating: | 3 A |

## Images

- [Product image 1](https://core-electronics.com.au/media/catalog/product/s/t/stackable_0.100_female_header_with_extra_0.3_spacer_2x20_pin_straight__pololu_2749__00.jpg)