If your ISP or cable provider supplied you with a cable modem, you're probably renting it from them and paying fees of up to $10 per month. In most cases there's nothing preventing you from just buying your own. With this 30% off deal, you may run the numbers and decide that today's the day you exercise this freedom.
The SURFboard SB6141 cable modem from Arris currently receives 4.5 out of 5 stars (9,000 reviews on Amazon). List price is $99.99, but with 31% off you can buy it now for just $69.99. At this price, it may pay for itself in just months. SURFboard supports IPv6, the latest internet standard. DOCSIS 3.0 technology provides eight downstream channels and four upstream channels. Data rates clock in at 343 Mbps download and 131 Mbps upload, depending on your cable internet provider. So there's plenty of speed for streaming HD video, gaming, video-conferencing, shopping, etc.
Review the specs, and call your cable provider with compatibility questions. For example, it will work well with many major cable providers like Xfinity by Comcast, Time Warner, Cox, Brighthouse and many others, but not Verizon FiOS.
Product reviews on Amazon appear to support the product's claims with regard to speed, ease of installation, and also success with eliminating those monthly rental fees with many major cable providers. See the Arris SURFboard on Amazon for more information as well as buying options.