diff --git a/main.c b/main.c
index 9b58d78..bb5580b 100644
--- a/main.c
+++ b/main.c
@@ -1656,6 +1656,7 @@ void set_electrical_delay(float picoseconds)
     electrical_delay = picoseconds;
     force_set_markmap();
   }
+  redraw_request |= REDRAW_MARKER;
 }
 
 float get_electrical_delay(void)
diff --git a/nanovna.h b/nanovna.h
index f9e31ae..524b2aa 100644
--- a/nanovna.h
+++ b/nanovna.h
@@ -74,7 +74,7 @@ void cal_collect(int type);
 void cal_done(void);
 
 #define MAX_FREQ_TYPE 5
-enum {
+enum stimulus_type {
   ST_START=0, ST_STOP, ST_CENTER, ST_SPAN, ST_CW
 };
 
@@ -109,7 +109,7 @@ extern int8_t sweep_enabled;
 extern void ui_init(void);
 extern void ui_process(void);
 
-enum { OP_NONE = 0, OP_LEVER, OP_TOUCH, OP_FREQCHANGE };
+enum opreq { OP_NONE = 0, OP_LEVER, OP_TOUCH, OP_FREQCHANGE };
 extern uint8_t operation_requested;
 
 /*
@@ -208,7 +208,7 @@ extern const uint16_t numfont16x22[];
 #define TRACES_MAX 4
 
 #define MAX_TRACE_TYPE 12
-enum {
+enum trace_type {
   TRC_LOGMAG=0, TRC_PHASE, TRC_DELAY, TRC_SMITH, TRC_POLAR, TRC_LINEAR, TRC_SWR, TRC_REAL, TRC_IMAG, TRC_R, TRC_X, TRC_OFF
 };
 // Mask for define rectangular plot
@@ -224,7 +224,7 @@ enum {
 // Electrical Delay
 // Phase
 
-typedef struct {
+typedef struct trace {
   uint8_t enabled;
   uint8_t type;
   uint8_t channel;
@@ -233,7 +233,7 @@ typedef struct {
   float refpos;
 } trace_t;
 
-typedef struct {
+typedef struct config {
   int32_t magic;
   uint16_t dac_value;
   uint16_t grid_color;
@@ -269,7 +269,7 @@ float groupdelay_from_array(int i, float array[POINTS_COUNT][2]);
 
 #define MARKERS_MAX 4
 
-typedef struct {
+typedef struct marker {
   int8_t enabled;
   int16_t index;
   uint32_t frequency;
@@ -367,7 +367,7 @@ void show_logo(void);
  */
 #define SAVEAREA_MAX 5
 
-typedef struct {
+typedef struct properties {
   uint32_t magic;
   uint32_t _frequency0;
   uint32_t _frequency1;
@@ -434,16 +434,16 @@ void clear_all_config_prop_data(void);
  */
 
 // lever_mode
-enum {
-  LM_MARKER, LM_SEARCH, LM_CENTER, LM_SPAN
+enum lever_mode {
+  LM_MARKER, LM_SEARCH, LM_CENTER, LM_SPAN, LM_EDELAY
 };
 
 // marker smith value format
-enum {
+enum marker_smithvalue {
   MS_LIN, MS_LOG, MS_REIM, MS_RX, MS_RLC
 };
 
-typedef struct {
+typedef struct uistat {
   int8_t digit; /* 0~5 */
   int8_t digit_mode;
   int8_t current_trace; /* 0..3 */
diff --git a/plot.c b/plot.c
index b696397..70f5e31 100644
--- a/plot.c
+++ b/plot.c
@@ -1574,6 +1574,10 @@ cell_draw_marker_info(int x0, int y0)
     int xpos = 21 + CELLOFFSETX - x0;
     int ypos = 1 + ((j+1)/2)*(FONT_GET_HEIGHT+1) - y0;
 
+    if (uistat.lever_mode == LM_EDELAY)
+      cell_drawstring(S_SARROW, xpos, ypos);
+    xpos += 5;
+
     float light_speed_ps = 299792458e-12; //(m/ps)
     plot_printf(buf, sizeof buf, "Edelay %Fs %Fm", electrical_delay * 1e-12,
                                                   electrical_delay * light_speed_ps * velocity_factor);
diff --git a/ui.c b/ui.c
index 24c59a6..681c8bb 100644
--- a/ui.c
+++ b/ui.c
@@ -1731,6 +1731,23 @@ lever_move(int status, int mode)
   }
 }
 
+#define STEPRATIO 0.2
+
+static void
+lever_edelay(int status)
+{
+  float value = get_electrical_delay();
+  float ratio = STEPRATIO;
+  if (value < 0)
+    ratio = -ratio;
+  if (status & EVT_UP) {
+    value = (1 - ratio) * value;
+  } else if (status & EVT_DOWN) {
+    value = (1 + ratio) * value;
+  }
+  set_electrical_delay(value);
+}
+
 static void
 ui_process_normal(void)
 {
@@ -1749,7 +1766,10 @@ ui_process_normal(void)
         if (FREQ_IS_STARTSTOP())
           lever_move(status, ST_STOP);
         else
-         lever_zoom_span(status);
+        lever_zoom_span(status);
+        break;
+      case LM_EDELAY:
+        lever_edelay(status);
         break;
       }
     }
@@ -2120,7 +2140,10 @@ touch_lever_mode_select(void)
     return TRUE;
   }
   if (touch_y < 15) {
-    select_lever_mode(LM_MARKER);
+    if (touch_x < FREQUENCIES_XPOS2 && get_electrical_delay() != 0.0) {
+      select_lever_mode(LM_EDELAY);
+    } else 
+      select_lever_mode(LM_MARKER);
     return TRUE;
   }
   return FALSE;