The Mamiya/Sekor auto XTL was introduced in April 1971. It was the first shutter-priority auto-exposure 35mm SLR camera with both spot and average TTL metering systems inherited from the Mamiya/Sekor DTL series cameras. The ES series lenses used a bayonet-type mount instead of the M42 screw mount of the TL/DTL series cameras.
The Mamiya AUTO X1000 (without the Sekor name), introduced in 1975, was similar to the auto XTL in most functions but featured all-black finish instead of black-and-chrome of the auto XTL.