diff --git a/_if/0253_sam3u2c_mkit_dk_dongle_nrf5x_0x5000.bin b/_if/0253_sam3u2c_mkit_dk_dongle_nrf5x_0x5000.bin
new file mode 100644
index 0000000..0423615
Binary files /dev/null and b/_if/0253_sam3u2c_mkit_dk_dongle_nrf5x_0x5000.bin differ
diff --git a/_if/nrf5x_atsam3u2c_if_mbed_V0221_11012017.bin b/_if/nrf5x_atsam3u2c_if_mbed_V0221_11012017.bin
deleted file mode 100644
index 9333ae5..0000000
Binary files a/_if/nrf5x_atsam3u2c_if_mbed_V0221_11012017.bin and /dev/null differ
diff --git a/package-lock.json b/package-lock.json
index 7b8d0bb..f8ec34d 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "web-bluetooth-dfu",
-  "version": "1.2.1-next.b285922.0",
+  "version": "1.2.1-next.4bf5039.0",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
diff --git a/package.json b/package.json
index 2c47bc1..ea6ec36 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "web-bluetooth-dfu",
-  "version": "1.2.1-next.b285922.0",
+  "version": "1.2.1-next.4bf5039.0",
   "description": "Device firmware update with Web Bluetooth",
   "homepage": "https://thegecko.github.io/web-bluetooth-dfu/",
   "author": "Rob Moran <github@thegecko.org>",