Lubrication of Model 28, BRPE, and CX Teletype equipment is to be accomplished using KS7470 Oil and 7471 Grease according to the following schedule: 60 wpm: 3000 hrs. or 1 yr* 75 wpm: 2400 hrs. or 9 mo* 100 wpm: 1500 hrs. or 6 mo* 1000 wpm: 150 hrs. or 1 mo* *Whichever occurs first. Per Teletype Corporation Bulletin 248B SECTION 573-104-701TC, September 1968