How important was Allied Lend-Lease to the USSR during WW2? Approximately how much of the gear in use by the Red Army was supplied by the other allied powers?

There's more to be said on the topic; you might like to start with some previous answers in the FAQ section Economy, Industry, and Lend-Lease.

"In WW2, who had greater industrial capacity, the Americans or the Soviets?", https://www.reddit.com/r/AskHistorians/comments/3ku09p/in_ww2_who_had_greater_industrial_capacity_the/cv0m243?context=3 , by /u/Georgy_K_Zhukov
"Soviet industrial might between 1940-1945?" at https://www.reddit.com/r/AskHistorians/comments/3mnhr2/soviet_industrial_might_between_19401945/cvgm5j2 by /u/Elm11, /u/iHistorian, and International_KB
"I often hear people say that the United States saved the USSR by lend-lease. How important was lend-lease to the Soviet war effort and is this claim anything more than just American propaganda?" at https://www.reddit.com/r/AskHistorians/comments/3pa76y/i_often_hear_people_say_that_the_united_states/cw4yywc?context=3 by iHistorian

Feel free to have follow-on questions. information, or debate! Listing these is not to discourage anything follow-up.

In the Reddit app, the # anchor doesn't work, so it goes to the top of the page, so you have to search for "lend" or such like.