Find out which items have trade restrictions and when they are tradable. Enter someone’s steam profile or trade link to load their inventory.
Steam profile or trade link:
Steam profile example: https://steamcommunity.com/id/gergelyszabo/
Trade link example: https://steamcommunity.com/tradeoffer/new/?partner=75764727&token=tx0asz7q
Or check an inventory directly by link.
What is a trade lock? At the end of March of 2018 Valve implemented a new update to CS:GO trading. They restrict the trading of newly received items by locking them to the account for 7 days. Once an inventory is loaded there is a countdown displayed for every item that marks the end of this seven-day trade cooldown.
This is what an inventory looks like when loaded and filtered to m4s, aks and m9s: