The t bar really makes a difference based on the design. Some are basic, sealed aluminum. Others are a durable plastic with many, many grooves in it to aid in holding much more water thereby assisting the volume of water the mop gets to hold.
|The T bar|
The mop is what really makes the window cleaner's job awesome. The mop can be made with a variety of materials that range from lamb skin, microfibers to scrubbers.