Representative of oil seal DL and DR English letter unit?

There will be a variety of letter codes on the model on the oil seal. these letters are of certain significance. The commonly used letter codes are as follows, each indicating different features of the oil seal:

DS: two-way rotary shaft seal vice lip.

ZD: two metal skeletons with inner and outer lips.

FB: a pair of lip exposed skeleton rotating shaft lip seal.

SP: inner package skeleton rotary axis lip sealing ring for multiple deputy lips.

MC: Shell seal ring.

DL: left crankshaft rotation.

DR: right crankshaft rotation.

QB: all rubber valve seals.

QC: rubber oil seal is not included in the inner wall of the skeleton.

RSDS: single spring reciprocating oil seal.

WD: rotating oil seal without spring.

FW: exposed skeleton Rotary shaft, oil seal with vice lip.