I've been searching in google if there is difference between oem and non-oem m988. Both states are fully compatible with I-spec. In Crc website they described that this is compatible with I-spec as well. It's just weird both lever arrive and the left lever is compatible with I-spec while the right it isn't... This annoying.... If i return this to tome I need to wait 6 weeks before I could get the new one. So meaning 6 weeks without riding my mountain bike... I won't able to do that because 3 to 4 time a week I ride my bike.