The Half Fare Travel Card is a separate product, that is a discount card, that gives you a discount of up to 50% on transport tickets. This card also give you 50% off on other trips you intend to do in Switzerland, and also on mountain transportation.
It costs 120,- so if it is worth it for you is something for you to figure out.
As you can see you can buy the Saver Day Pass with, and without the discount. With the discount it is 34, and without it is 52. So If you do not intend to get the Half Fare Card you should get the one without the Half Fare Discount.