Just buy this!
WOW, just what was needed!  Like many others I work from home more these days and my previous setup was less than ideal.  I started searching for an armrest mouse pad and found a lot of options but something about this product just jumped ahead of the others.  Started reading the reviews and found this was handmade, some even to order.  I contacted the seller, sent him a pic of my chair as it's not quite like others in that the arms are slanted towards the seat.  After some chatting the seller suggested a custom 10x10 size.  It arrived yesterday and I can already tell the stiffness in my shoulder is gone because of using this product.  My arm can rest on the armrest with the pad and mouse directly aligned and works like a charm.  The seller is extremely easy to work with and the product is very well made and sturdy.  Very highly recommend
Rating: 5 stars