DBR TM Designworks Chain Guide SX GP Honda D Black : (07->C) CRF250 R/X, (07->C) CRF450 R/RX/L, (08-14) CRF450 X

Factory Edition SX series chain guides are designed for Motocross and Supercross.
Ultra compact & slim solid body guide with a non-replaceable wear pad.
Lightweight design is 15 grams lighter than the stock Honda guide.
Our exclusive return memory formula plastic absorbs impacts and reduces chain drag.
Updated upper wear pad protects each side of sprocket for maximum deflection of rocks and dirt in guide.
The bottom wear pad is longer than stock, so chains jumping the sprocket are virtually eliminated.
Used and tested by the 2013-2018 Geico Motocross Race Team.
Utility Patent # 9469779 in USA and EU Patent # ECD2583716-0001
The Factory Edition SX guide is for track riding only. 
For off-road riding check out our FE #1 or #2 rear chain guide options.

Fitment From Parts Finder:
HONDA (07-Current) CRF 250R & CRF 450R