JaxJox DumbbellConnect Adjustable Dumbbells Give your dumbbells a serious upgrade with these JaxJox DumbbellConnect adjustable dumbbells ($330). The 50-pound weights are adjusted digitally, and they connect to the JaxJox app so you can track every rep and set. Image Source: bestbuy.com JaxJox DumbbellConnect adjustable dumbbells $330 from bestbuy.com Buy Now