Here is a list of some of the largest IoT device manufacturers, along with their websites:

1. Cisco Systems https://www.cisco.com/
2. Samsung Electronics https://www.samsung.com/
3. Intel Corporation https://www.intel.com/
4. Siemens AG https://www.siemens.com/
5. IBM Corporation https://www.ibm.com/
6. Bosch https://www.bosch.com/
7. Huawei Technologies  https://www.huawei.com/
8. Amazon (Amazon Web Services) https://aws.amazon.com/
9. Microsoft  https://www.microsoft.com/
10. Dell Technologies https://www.delltechnologies.com/
11. Honeywell  https://www.honeywell.com/
12. General Electric (GE)  https://www.ge.com/
13. ARM Holdings  https://www.arm.com/
14. Qualcomm  https://www.qualcomm.com/
15. Texas Instruments  https://www.ti.com/