This folded paper element provides superior filtration over the stock filter because it has a much larger surface area that allows it to work for much longer before it gets clogged like the OE filter. Fits 1941-1964 Harley Big Twin Knucklehead & Panhead Models. Replacement filter for Harley External “Can” or Canister-Style Oil Filters (Part# 63800-48) found on early Harley models. This filter is a direct replacement for HD Oil Filter Part # 63840-48A SOLD INDIVIDUALLY