The O rings closest in size I found are these: https://www.aliexpress.com/store/product/LUJX-R-10pcs-Sealing-Flat-Gasket-White-Silicone-O-Ring-Seal-Washer-Bellows-Inlet-Hose-1/3144005_32893451772.html?spm=2114.12010615.8148356.9.5e302d41IBxLWL They may be to big with 22x28x2 mm, but the O rings with the correct size are only round: https://www.aliexpress.com/item/White-Silicon-1-5mm-Thickness-19-20-21-22-23-24-25-26-27-28mm-Outside/32803654515.html?spm=2114.search0104.3.15.4497dc10UcwLx1&ws_ab_test=searchweb0_0,searchweb201602_5_10065_10068_10130_10547_319_317_10548_10696_10192_5728811_10190_453_10084_454_10083_10618_10307_10820_10301_10821_10303_537_536_5733215_5733315_328_10059_10884_5731015_5733115_10887_100031_5733415_321_322_5730015_10103_5733515_5733615,searchweb201603_55,ppcSwitch_0&algo_expid=a130f1a1-3fa0-4d57-86eb-463f6d148e43-2&algo_pvid=a130f1a1-3fa0-4d57-86eb-463f6d148e43