K&N E-3988 RK Series Oval Tapered Air Filter for Harley-Davidson Touring Dyna

Vehicle Fitment

• 2008-2017 Harley-Davidson Touring Models (FLHR Road King, FLHRC Road King Classic, FLHX Street Glide, FLHXS Street Glide Special, FLHTC Electra Glide Classic, FLHTCU Electra Glide Ultra Classic, FLHTK Ultra Limited/Electra Glide Ultra Limited, FLTRU Road Glide Ultra, FLTRXS Road Glide Special, FLRT Freewheeler, FLHT Electra Glide Standard, FLHRSE4 Screamin Eagle Road King) - 96CI, 103CI Twin Cam
• 2016-2017 Harley-Davidson Softail Models (FLSTF Fat Boy, FLSTFB Fat Boy Lo, FLSTC Heritage Softail Classic, FLSTN Softail Deluxe, FLS Softail Slim, FLSS Softail Slim S) - 103CI Twin Cam
• 2001-2017 Harley-Davidson Dyna Models (FXD, FXDB, FXDC, FXDF, FXDL, FXDS, FXDWG and variants) - 88CI, 96CI, 103CI Twin Cam
• 2001-2015 Harley-Davidson Softail Models (FLST, FXST, FXSTB, FXSTC, FXSTD, FXSTS and variants) - 88CI, 96CI, 103CI Twin Cam

Fitment Notes

• This is a replacement filter element for K&N RK-3952 and RK-3953 Street Metal air cleaner assemblies only - the RK assembly must already be installed on the motorcycle
• Not compatible with stock OEM Harley-Davidson air cleaner housings - requires K&N RK-3952 or RK-3953 housing
• No jet changes required when using this filter element as a replacement in an existing RK Series assembly
• Verify your installed RK assembly part number before ordering to confirm correct filter match

Features

• Multi-layer oiled cotton gauze media delivers up to 50% more airflow than standard paper filters
• Oval tapered profile engineered specifically for K&N RK-3952 and RK-3953 air cleaner housings
• Washable and reusable - engineered to last the lifetime of your motorcycle
• Pre-oiled and ready to install straight out of the box
• Designed to maintain increased horsepower and throttle response of the RK Series intake system
• Ideal for extended use in dirty and dusty off-road and open-road riding conditions
• No jet changes required as a replacement element
• Backed by K&N's Million Mile Limited Warranty

Specifications

• Shape: Oval Tapered
• Base Outside Length: 10.00 in. (254 mm)
• Base Outside Width: 6.00 in. (152 mm)
• Height: 2.375 in. (60 mm)
• Top Outside Diameter: 9.313 in. (237 mm)
• Filter Material: Multi-layer oiled cotton gauze
• Filter Color: Red
• Compatible Assemblies: K&N RK-3952, RK-3953

Included Components

• 1x K&N E-3988 Oval Tapered Replacement Air Filter Element

Product Description

The K&N E-3988 is the dedicated replacement filter element for K&N's RK-3952 and RK-3953 Street Metal air cleaner assemblies, designed for a wide range of Harley-Davidson Touring, Softail, and Dyna models from 2001 through 2017. Built with K&N's signature multi-layer oiled cotton gauze construction, this oval tapered element delivers superior airflow and filtration performance to keep your RK Series intake system operating at peak efficiency. It drops directly into the existing RK housing with no modifications required.

Washable and reusable, the E-3988 arrives pre-oiled and ready to install. It is purpose-engineered to maintain the horsepower and throttle response gains delivered by the RK-3952 and RK-3953 systems, and requires no carburetor or fuel injection retuning as a replacement element. Backed by K&N's Million Mile Limited Warranty, this filter is the correct long-term service solution for Harley-Davidson riders running either of these K&N Street Metal intake assemblies.