X0306 4 2022-03-11 0 0001816581 Ouster, Inc. OUST 0001334330 Heystee Susan 350 TREAT AVENUE SAN FRANCISCO CA 94110 1 0 0 0 Common Stock 2022-03-11 4 M 0 1891 0.00 A 445788 D Common Stock 2022-03-11 4 M 0 3862 0.00 A 449650 D Restricted Stock Units 2022-03-11 4 M 0 1891 0.00 D Common Stock 1891 0 D Restricted Stock Units 2022-03-11 4 M 0 3862 0.00 D Common Stock 3862 0 D Each restricted stock unit ("RSU") represents a contingent right to receive one share of common stock. The reporting person previously reported certain awards of RSUs in Table II of Form 4, but has elected to report them in Table I going forward. The total reported in Column 5 of Table I has been updated to include 15,131 RSUs that would have otherwise been reported in Column 9 of Table II from an original grant of 22,696 RSUs granted on March 11, 2021 which have vested or will vest as to 1/12 of the total number of RSUs on each quarterly anniversary after March 11, 2021. The grant of RSUs has vested in full. /s/ Adam Dolinko, Attorney-in-Fact 2022-03-15