>>316514438
Here's a silicone one from vrcover:
https://www.amazon.co.uk/VR-Cover-Silicone-Valve-Index/dp/B08B8DH74Q/ref=sr_1_7?dchild=1&keywords=index+vr+cover&qid=1607430802&sr=8-7

Here's a knock-off leather one from AMVR. They're fairly reliable and I've used them for my Rift S and Q2 accessories:
https://www.amazon.co.uk/AMVR-Interface-Replacement-Anti-Leakage-Protective/dp/B08CKP6TLV/ref=sr_1_11?dchild=1&keywords=index+vr+cover&qid=1607430802&sr=8-11