Features: 【Perfect Fitment】This compression test adapter is designed for 6.0L Diesel Engines. Suitable for 2003-2006 pickups and vans with 6.0-liter diesel engines. Replace for 303-757. 【Excellent Performance】With the glow plug removed, the compression test adapter can be used to connect the #5021 gauge to a glow plug port for compression testing. 【Excellent Performance】With the glow plug removed, the compression test adapter can be used to connect the #5021 gauge to a glow plug port for compression testing. .