The DCF14 Eureka filter fits the bagless Eureka 430 series upright bagless vacuum cleaners.
The DCF-14 and the DCF-10 filter are the same exact size.
Older Optima vacuum came with a DCF-10 which is now a DCF-14 filter.
Compare to Eureka filter part # 79982, 75273-1, 62731A, 62731B, 62731 and 62396
Universal Eureka DCF-14 filter replacement part. Examples of Eureka Optima 430 series lightweight bagless vacuum that use a DCF14:
Eureka Optima - 431BX, 431F, 437AZ, 431DX, 431F, 437AZ
Eureka Optima Pet Lover - 439AZ and Pet Lover Oh! - 439AZ