LINEAR model DR4 receiver. It receives using on frequency 310 MHz.
The warranty on the DR4 garage door receiver is 1 year from LINEAR.
The model is still available.
LINEAR model DR4 receiver instructions and owners manual in PDF format at NO CHARGE!
VIEW / DOWNLOAD by clicking HERE
linear_dr4_om.pdf
(0.10 MB in English) This requires Acrobat 10 or higher