"The current team must extend a "qualifying offer" to a restricted free agent to retain negotiating rights to that player. Qualifying offers are for one year contracts. The minimum salary for the qualifying offer depends on the player's prior year salary.
Players who earned less than $660,000 in the previous season must be offered 110 percent of last season's salary. Players making up to $1 million must be offered 105 percent. Players making over $1 million must be offered 100 percent.
If the qualifying offer is not made, the player becomes an unrestricted free agent.
If the player rejects a qualifying offer, he remains a restricted free agent"
A different contract can be negotiated after a qualifying offer is extended to a player.
Edit: source https://en.m.wikiped..._free_agent#NHL