You are downloading the WaLock XAP file v220.127.116.11 for Windows Phone. WaLock is a free and useful Utilities & Tools app: WaLock is a simple application to lock your whatsapp messaging app. Simply put a master password and You are done! Your Whatsapp is protected ... You can now download the offline XAP file to install & try it.
Download Locations for WaLock 18.104.22.168 XAP file
Important Notice: Now Due To Unspecified Limitations, You Can Not Use The Offline XAP File To Install It Any More.
To try to install it manually from an SD card, you should choose one of the server location above to get the offline WaLock XAP file, move the file to your phone's SD card and then tap 'Install local apps' in the phone's App list.