Как называется данный элемент управления?

' НА ЭЛЕМЕНТЕ УПРАВЛЕНИЯ
    Private Sub RectangleShape1_MouseEnter(ByVal sender As Object, ByVal e As System.EventArgs) Handles RectangleShape1.MouseEnter
        RectangleShape1.BorderColor = Color.CornflowerBlue
    End Sub
    Private Sub RectangleShape2_MouseEnter(ByVal sender As Object, ByVal e As System.EventArgs) Handles RectangleShape2.MouseEnter
        RectangleShape2.BorderColor = Color.CornflowerBlue
    End Sub
    Private Sub RectangleShape3_MouseEnter(ByVal sender As Object, ByVal e As System.EventArgs) Handles RectangleShape3.MouseEnter
        RectangleShape3.BorderColor = Color.CornflowerBlue
    End Sub
    'ПОКИДАЕТ ЭЛЕМЕНТ УПРАВЛЕНИЯ
    Private Sub RectangleShape1_MouseLeave(ByVal sender As Object, ByVal e As System.EventArgs) Handles RectangleShape1.MouseLeave
        RectangleShape1.BorderColor = Color.Transparent
    End Sub
    Private Sub RectangleShape2_MouseLeave(ByVal sender As Object, ByVal e As System.EventArgs) Handles RectangleShape2.MouseLeave
        RectangleShape2.BorderColor = Color.Transparent
    End Sub
    Private Sub RectangleShape3_MouseLeave(ByVal sender As Object, ByVal e As System.EventArgs) Handles RectangleShape3.MouseLeave
        RectangleShape3.BorderColor = Color.Transparent
    End Sub

Public Class Form1
    Private timer1 As Timer = New Timer
    Private mouse_in As Boolean = False
    Private sender_herender As Object
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        timer1.Enabled = True
        timer1.Interval = 50
        AddHandler timer1.Tick, AddressOf mouse_in_label
        For Each Label In Me.Controls
            Label.backcolor = Color.FromArgb(255, 255, 255)
        Next
    End Sub
 
    Private Sub mouse_in_label()
        If mouse_in Then
            If Me.Controls(sender_herender).BackColor.G > 0 Then Me.Controls(sender_herender).BackColor = Color.FromArgb(Me.Controls(sender_herender).BackColor.R - 5, Me.Controls(sender_herender).BackColor.G - 5, Me.Controls(sender_herender).BackColor.B)
        End If
        For Each Label In Me.Controls
            If Label.name IsNot sender_herender Then
                If Label.backcolor.G < 255 Then Label.backcolor = Color.FromArgb(Label.backcolor.R + 5, Label.backcolor.G + 5, Label.backcolor.B)
            End If
        Next
    End Sub
 
    Private Sub Label_MouseEnter(ByVal sender As Object, ByVal e As System.EventArgs) Handles Label3.MouseEnter, Label1.MouseEnter, Label2.MouseEnter, Label4.MouseEnter
        mouse_in = True
        sender_herender = sender.name
    End Sub
 
    Private Sub Label_MouseLeave(ByVal sender As Object, ByVal e As System.EventArgs) Handles Label1.MouseLeave, Label3.MouseLeave, Label2.MouseLeave, Label4.MouseLeave
        mouse_in = False
        sender_herender = Nothing
    End Sub
End Class