For Lord Shiva, there are shivlings/lingam that people use for devotional worship.
Are there any comparable devotional objects that many people use to worship Lord Vishnu, or objects that represent Lord Vishnu (other than, for example, a murti that is shaped in his image)?
(Apologies if my question seems basic; there is much for me to learn but I would be grateful for any information or suggestions for further reading. I did search the site for an answer before posting this question.)