You can change the strap, there is a second strap included with the purchase. If you want to change it anyway, I recommend a leather strap or similar, as the rubber strap supplied has a flair for hair... ;-)
For the watch size 42mm (like this product) you need a strap of 20mm width, for the larger model 46mm a strap of 22mm width.
If you are planning to buy this product, I can recommend this. I am absolutely satisfied, the watch needs to be charged every second night. Have fun.