Nearly a third of women are unsure how to check themselves for the early signs of breast cancer, a survey shows.
Research, carried out by the Genesis Appeal, found that although women are aware of breast cancer, many have no idea how to detect it.
Around 35% of women said they do not check for lumps regularly, while 33% said they are unsure how to do it.
Only a third who examine their breasts regularly said they check important areas, such as under the armpit.
And just 20% of women who carry out self-examinations do so at the same time every month - a key factor in detecting changes.
To help combat the lack of knowledge surrounding self examination, Lloydspharmacy and the Genesis Appeal have produced the DVD, accompanied by a special gel-based glove, which will help women carry out self-examinations of their breasts.
TV GP Dr Chris Steele, who is backing the campaign, said that while awareness of breast cancer is at an all-time high, knowledge about how to detect it has remained consistently low.
Money raised from the sale of the glove and DVD will help fund the charity's new Genesis Prevention Centre in Manchester.