If you are looking for the difference between the ceramic capacitors K104K15X7RF53H5 and K104K15X7RF55H5 from Vishay Beyschlag/Draloric/BC Components, then the following information can clarify any concerns:
The only difference between both the above-mentioned parts is of “3” and “5” which are highlighted by bold letters. Here “3” signifies 30 mm lead length and “5” signifies 5.0 mm lead length.
Reference: Page No. 15 in the General Information Sheet
Applicable Part Numbers
K104K15X7RF55H5-ND
BC3323-ND