diff --git a/Package.swift b/Package.swift
index c01d3fe..ff66843 100644
--- a/Package.swift
+++ b/Package.swift
@@ -1,4 +1,4 @@
-// swift-tools-version:5.3
+// swift-tools-version:5.9
 //  Package.swift
 //  Printer
 //
@@ -10,14 +10,13 @@ import PackageDescription
 
 let package = Package(
     name: "Printer",
-    platforms: [.iOS(.v9)],
+    platforms: [.iOS(.v17)],
     products: [
         .library(
             name: "Printer",
             targets: ["Printer"]
         )
     ],
-    dependencies: [],
     targets: [
         .target(
             name: "Printer",
diff --git a/Sources/Printer/Hardware/Bluetooth/BluetoothCentralManagerDelegate.swift b/Sources/Printer/Hardware/Bluetooth/BluetoothCentralManagerDelegate.swift
index 3b8def9..5b4a486 100644
--- a/Sources/Printer/Hardware/Bluetooth/BluetoothCentralManagerDelegate.swift
+++ b/Sources/Printer/Hardware/Bluetooth/BluetoothCentralManagerDelegate.swift
@@ -9,6 +9,7 @@
 import CoreBluetooth
 import Foundation
 
+@Observable
 class BluetoothCentralManagerDelegate: NSObject, CBCentralManagerDelegate {
     enum UserDefaultKey {
         static let autoConnectUUID = "auto.connect.uuid"
@@ -18,12 +19,12 @@ class BluetoothCentralManagerDelegate: NSObject, CBCentralManagerDelegate {
 
     var peripheralDelegate: BluetoothPeripheralDelegate?
 
-    open var centralManagerDidUpdateState: ((CBCentralManager) -> Void)?
-    open var centralManagerDidDiscoverPeripheralWithAdvertisementDataAndRSSI:
+    var centralManagerDidUpdateState: ((CBCentralManager) -> Void)?
+    var centralManagerDidDiscoverPeripheralWithAdvertisementDataAndRSSI:
         ((CBCentralManager, CBPeripheral, [String: Any], NSNumber) -> Void)?
-    open var centralManagerDidConnectPeripheral: ((CBCentralManager, CBPeripheral) -> Void)?
-    open var centralManagerDidFailToConnectPeripheralWithError: ((CBCentralManager, CBPeripheral, Error?) -> Void)?
-    open var centralManagerDidDisConnectPeripheralWithError: ((CBCentralManager, CBPeripheral, Error?) -> Void)?
+    var centralManagerDidConnectPeripheral: ((CBCentralManager, CBPeripheral) -> Void)?
+    var centralManagerDidFailToConnectPeripheralWithError: ((CBCentralManager, CBPeripheral, Error?) -> Void)?
+    var centralManagerDidDisConnectPeripheralWithError: ((CBCentralManager, CBPeripheral, Error?) -> Void)?
 
     typealias PeripheralChangeBlock = (UUID) -> Void
 
diff --git a/Sources/Printer/Hardware/Bluetooth/BluetoothPeripheralDelegate.swift b/Sources/Printer/Hardware/Bluetooth/BluetoothPeripheralDelegate.swift
index 94cf955..b1ff9f4 100644
--- a/Sources/Printer/Hardware/Bluetooth/BluetoothPeripheralDelegate.swift
+++ b/Sources/Printer/Hardware/Bluetooth/BluetoothPeripheralDelegate.swift
@@ -9,6 +9,7 @@
 import CoreBluetooth
 import Foundation
 
+@Observable
 class BluetoothPeripheralDelegate: NSObject, CBPeripheralDelegate {
     private var services: Set<String>!
     private var characteristics: Set<CBUUID>?
diff --git a/Sources/Printer/Hardware/Bluetooth/BluetoothPrinterManager.swift b/Sources/Printer/Hardware/Bluetooth/BluetoothPrinterManager.swift
index 7121dd0..0fec0c7 100644
--- a/Sources/Printer/Hardware/Bluetooth/BluetoothPrinterManager.swift
+++ b/Sources/Printer/Hardware/Bluetooth/BluetoothPrinterManager.swift
@@ -65,6 +65,7 @@ public extension BluetoothPrinterManager {
     static var specifiedCharacteristics: Set<String>?
 }
 
+@Observable
 public class BluetoothPrinterManager {
     public var updateHandler: (() -> Void)?
 
diff --git a/Sources/Printer/Receipt/QRCode.swift b/Sources/Printer/Receipt/QRCode.swift
index 6ed7aec..a0aff9e 100644
--- a/Sources/Printer/Receipt/QRCode.swift
+++ b/Sources/Printer/Receipt/QRCode.swift
@@ -20,19 +20,31 @@ public struct QRCode: ReceiptItem {
         case q = 50 // 25%
         case h = 51 // 30%
     }
+    public enum ModuleSize: UInt8 {
+        case s1D = 0x1D
+        case s28 = 0x28
+        case s6B = 0x6B
+        case s03 = 0x03
+        case s00 = 0x00
+        case s31 = 0x31
+        case s43 = 0x43
+    }
     
     public let m: Model
+    public let moduleSize: ModuleSize
+
     public let content: String
     public let level: RecoveryLevel
     
     //  Sets the size of the module for QR Code to n dots. width == height
     public let width: UInt8
     
-    public init(content: String, width: UInt8 = 200, recovery level: RecoveryLevel = .m, m: Model = .m_2) {
+    public init(content: String, width: UInt8 = 200, recovery level: RecoveryLevel = .m, m: Model = .m_2, moduleSize: ModuleSize = .s03) {
         self.content = content
         self.m = m
         self.width = width
         self.level = level
+        self.moduleSize = moduleSize
     }
     
     //  https://reference.epson-biz.com/modules/ref_escpos/index.php?content_id=145
@@ -42,11 +54,11 @@ public struct QRCode: ReceiptItem {
         }
         // Code type for QR code
        
-        // Set dot size
-        var data = [29, 40, 107, 4, 0, 49, 65, m.rawValue, width]
+        // Select the model 
+        var data = [29, 40, 107, 4, 0, 49, 65, m.rawValue, 0]
 
-        //  Select the model
-        data += [29, 40, 107, 3, 0, 49, 65, m.rawValue]
+        // Set module size
+        data += [29, 40, 107, 3, 0, 49, 67, moduleSize.rawValue]
         
         //  Select the error correction level
         data += [29, 40, 107, 3, 0, 49, 69, level.rawValue]
@@ -59,7 +71,7 @@ public struct QRCode: ReceiptItem {
         data += ([29, 40, 107, pl, ph, 49, 80, 48] + contentData)
         
         // Print the symbol data in the symbol storage area
-        data += [29, 40, 107, 3, 0, 49, 81, 0]
+        data += [29, 40, 107, 3, 0, 49, 81, 48]
         
         return data
     }