This is the 8997th most frequent Russian word.
резик
"Резик" is slang for "condom" in Russian.
In this sentence, 'резик' is used colloquially to refer to a 'rubber case' or 'small container'.
Он всегда носит с собой резик на случай дождя.
He always carries a small rubber case for emergencies in case of rain.
Here, 'резик' refers to rubber material in general, potentially for patching or sealing.
Не забудь, резик может пригодиться для ремонта.
Don't forget, the rubber material might be useful for repairs.
In this example, 'резик' denotes a piece or part made of rubber to fix something.