diff --git a/src/index.ts b/src/index.ts
index 15e25d2..8f112ad 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -250,7 +250,7 @@ export default class Updater {
                                         if (dataView[0] == 1) {
                                                 // send file
                                                 this.sendNextPacket();
-                                                progressCallback(`Sending (${Math.floor((this._fileProgress *100)/this._fileSize)}%), ${this._fileProgress} / ${this._fileSize}`);
+                                                progressCallback(`MTU: ${this._packetSize}; Sending (${Math.floor((this._fileProgress *100)/this._fileSize)}%), ${this._fileProgress} / ${this._fileSize}`);
                                         } else if (dataView[0] == 2) {
                                                 // done logic
                                                 console.log(`progress >= filesize: ${this._fileProgress} vs ${this._fileSize}`);