No, not the new Bond film but this stuff
Having gone from a Garmin Premium HR strap to the Polar HR strap as recommended by our resident shoe expert, CCS, readings remained stable for a while but over the past few weeks they've become more erratic with many peaks/troughs/dropouts so I began some interweb research. Many hours later having perused various specialist interest sites, I happened upon DC Rainmaker's blog about erratic HR readings and the reasons why. One 250g tube procured from a well known interweb auction site for the princely sum of £6.98 including delivery, a few little blobs applied to the strap before riding and my readings are normal again
To sum up: it works a treat and is good value