diff --git a/frc971/control_loops/BUILD b/frc971/control_loops/BUILD
index 16673df..12d3a4b 100644
--- a/frc971/control_loops/BUILD
+++ b/frc971/control_loops/BUILD
@@ -133,7 +133,7 @@
     hdrs = [
         "state_feedback_loop.h",
     ],
-    restricted_to = ["//tools:cortex-m4f"],
+    restricted_to = mcu_cpus,
     deps = [
         "//aos/common:macros",
         "//third_party/eigen",
diff --git a/motors/fet12/fet12.cc b/motors/fet12/fet12.cc
index f008379..889138e 100644
--- a/motors/fet12/fet12.cc
+++ b/motors/fet12/fet12.cc
@@ -241,7 +241,7 @@
 
   teensy::UsbDevice usb_device(0, 0x16c0, 0x0490);
   usb_device.SetManufacturer("FRC 971 Spartan Robotics");
-  usb_device.SetProduct("Pistol Grip Controller debug");
+  usb_device.SetProduct("FET12");
   teensy::AcmTty tty1(&usb_device);
   teensy::AcmTty tty2(&usb_device);
   global_stdout.store(&tty1, ::std::memory_order_release);
diff --git a/motors/fet12/power_wheels.cc b/motors/fet12/power_wheels.cc
index edfaf4e..668dbe6 100644
--- a/motors/fet12/power_wheels.cc
+++ b/motors/fet12/power_wheels.cc
@@ -117,7 +117,7 @@
 
   teensy::UsbDevice usb_device(0, 0x16c0, 0x0490);
   usb_device.SetManufacturer("FRC 971 Spartan Robotics");
-  usb_device.SetProduct("Pistol Grip Controller debug");
+  usb_device.SetProduct("FET12 power wheels mode");
   teensy::AcmTty tty1(&usb_device);
   teensy::AcmTty tty2(&usb_device);
   global_stdout.store(&tty1, ::std::memory_order_release);
diff --git a/third_party/GSL/BUILD b/third_party/GSL/BUILD
index 10fe510..62a28f3 100644
--- a/third_party/GSL/BUILD
+++ b/third_party/GSL/BUILD
@@ -1,8 +1,11 @@
 licenses(["notice"])
 
+load("//tools:environments.bzl", "mcu_cpus")
+
 cc_library(
     name = "GSL",
     hdrs = glob(["include/**"]),
+    compatible_with = mcu_cpus,
     includes = ["include"],
     visibility = ["//visibility:public"],
 )
diff --git a/tools/environments.bzl b/tools/environments.bzl
index 68e78de..c82a01b 100644
--- a/tools/environments.bzl
+++ b/tools/environments.bzl
@@ -1,5 +1,6 @@
 # Contains some helpers for working with environments.
 
 mcu_cpus = [
-  "@//tools:cortex-m4f",
+    "@//tools:cortex-m4f",
+    "@//tools:cortex-m4f-k22",
 ]