Enjoy! #FF-This hashtag mostly shows up on Fridays, which should give you a good indication of what one of the Fs means. The other stands for Follow, and the two combine to make the phrase Follow Friday.. Follow Friday is essentially a Twitter holiday with the aim of getting people to follow one another.
Technical. Original manufacturers part,390 Mhz frequency, 9-volt battery operated, part number 976LM a 977LM keypad is substituted per the manufacturers change, Color: Grey Works with all Liftmaster, Sears and Chamberlain garage door openers, utilizing the 390 Mhz frequency.echnical. Original manufacturers part,390 Mhz frequency, 9-volt battery operated, part number 976LM a 977LM keypad is substituted per the manufacturers change, Color: Grey Works with all Liftmaster, Sears and Chamberlain garage door openers, utilizing the 390 Mhz frequency.
Frequencies below 50MHz are used for reverse data and some return channel feeds (depending on your cable plant). Ingress in this range will possably raise the noise floor and could cause a modem/dct outage. Frequencies above 550MHz are typically used for digital carriers.