diff --git a/maria/instrument/bands/abs.yml b/maria/instrument/bands/abs.yml
new file mode 100644
index 0000000..8362c66
--- /dev/null
+++ b/maria/instrument/bands/abs.yml
@@ -0,0 +1,7 @@
+f150:
+  center: 150
+  width: 30
+  tau: 0
+  white_noise: 266.e-6 # in K_RJ s^-1/2
+  pink_noise: 1.e-1 # in K_RJ s^-1/2
+  efficiency: 0.5
diff --git a/maria/instrument/instruments.yml b/maria/instrument/instruments.yml
index 562f400..f0a7f29 100644
--- a/maria/instrument/instruments.yml
+++ b/maria/instrument/instruments.yml
@@ -2,14 +2,12 @@ ABS:
   aliases: ["abs"]
   description: Atacama B-Mode Search
   documentation: https://almascience.nrao.edu/about-alma/alma-basics
-  bands:
+  dets:
     abs:
-      n_dets: 250
-      center: 150
-      width: 10
-      efficiency: 1.9
+      field_of_view: 25
+      detector_geometry: hex
+      n: 250
       bands: [abs/f150]
-  field_of_view: 25
   geometry: hex
   primary_size: 0.5