The Canon Macrolite Adapter 67 attaches MT-24EX, MR-14EX or ML-3 to most 67mm filter size lenses.
Not recommended for use with the EF-28-80mm f/3.5-5.6, EF 28-70mm f/3.5-4.5, EF 35-70mm F/3.5-4.5, or FD 28-55mm f/3.5-4.5, or FD 35-70mm f/3.5-4.5; already built into the EF 50 f/2.8 Marco, EF 100mm f/2.8, EF-S 60mm f/2.8 USM Marco, EF 100mm f/2.8 USM Marco and MP-E 65mm lenses.