5-1/4" x 4-1/2" x 1" Paper Air Filter. Designed for 4 - 5.5 HP Briggs & Stratton Vertical Shaft and 3 & 5 HP Quantum Horizontal Shaft Engines with Horizontal Rewind. This filter effectively traps dirt, dust, and debris, ensuring optimal engine performance and longevity. It replaces Briggs #491588, 399959, and Quantum series No 121700, 122700, 124700.

• 5-1/4" x 4-1/2" x 1"
• Fits 4 - 5.5 HP Briggs & Stratton Vertical Shaft & 3 & 5 HP Quantum Horizontal Shaft Engines, with Horizontal Rewind
• Replaces Briggs #491588, 399959