Suction cup grab bars are a type of grab bar that uses suction cups to attach to a surface, rather than screws or other hardware. The weight capacity of suction cup grab bars can vary depending on the specific model and manufacturer. However, as a general guideline, most suction cup grab bars are designed to support a maximum weight of around 250-300 pounds (113-136 kg). 

It is important to note that the weight capacity of a suction cup grab bar can be affected by a variety of factors, such as the condition and cleanliness of the surface to which it is attached, and the strength and grip of the user. Additionally, suction cup grab bars may not be suitable for use on all surfaces and may not provide the same level of stability as a grab bar that is securely mounted with screws or other hardware. 

Therefore, it is important to carefully read the manufacturer’s instructions for the suction cup grab bar and to use it only as directed. Users should also regularly check the suction cups to ensure that they are securely attached and free from damage or wear. If a user requires more support or has a higher weight capacity requirement, they may want to consider a different type of grab bar that is designed for higher weight capacity and more secure mounting, such as a permanently mounted grab bar or a clamp-on grab bar.