Used to be the left or rt thing but not today !! I have seen both used !! Personally I don`t think it matters but sometimes you can tell by how its sized !! I would say unisex and let it go at that !! Mens sizes usually are small 14-141/2,, medium, 15-151/2,,large, 16-161/2 !! Ladies usually are small, medium, large ect !! Although different mfrs often use different variations !! Many use a European or Mexican designation depending on who their market is !!