2 Truck Upfitters Gas Props for Undercover Tonneau Covers ONLY. 27.5" Extended and 15.6" Compressed Length (Measured from Center of Ball mounts), 38 pounds of Pressure ea. Incl 4 Ball mounts!

Truck Upfitters Premium Gas Struts for Undercover Style Tonneau Covers (SE, Classic, Elite models) ONLY. These do NOT fit any other brand tonneau covers. Also, these do NOT fit the Ford Sport Trac Undercover Tonneau. Please measure your struts, from center of ball mount to center of ball mount, before replacing with these. Will NOT fit any fiberglass or any other brand tonneaus and lids.INSTALLATION INSTRUCTIONS:1. All gas lift spring CANNOT be compressed by hand, so please do not think they are defective because the won't close using hand/arm pressure. A LOT of pressure is required to compress these props!2. All undercover series gas spring need to be installed in the OPEN / EXTENDED position, so please do not try to compress and install them in the compressed position. Therefore, open your door to ensure your mounted props are EXTENDED.3. VERY IMPORTANT: Use another person's help (or 2 people for heavier doors) to hold the door in the extended position while you remove the old gas lift shocks. Do NOT use a broomstick or any other device to hold the door open while you remove the prop. it may fall & cause you or your vehicle serious damage.4.To remove your old gas prop, use a small screwdriver to lift up on the retaining band, then pull the gas prop end away from the mount. You do not need to remove the retaining metal band, just lift it away from the nylon head enough to allow the head to come off.5. To install, place the replacement gas struts so that the wide (black part) of the gas prop (the body) is on the top, and the shaft (silver part) is on the bottom when the door is in the closed/resting position. This is so that the oil in the body will keep the seal wet, preventing it from cracking & allowing all of the pre-charged air out, resulting in failure. After aligning properly, press the nylon end head of each shock onto the 10mm ball mount. You will NOT need to lift up on the band to install.

• CHECK YOUR LENGTHS AND PRESSURE BEFORE ORDERING. THESE ARE NOT COMPATIBLE WITH ALL PLASTIC TONNEAU COVERS! THE MEASUREMENTS ARE FROM CENTER OF BALL MOUNT TO CENTER OF BALL MOUNT, NOT FROM END TO END OF STRUT! SEE PICTURE!
• Truck Upfitters Pair of 38 pound gas struts. 27.5" extended length and 15.6" compressed length (measured from center of each ball mount). 29" overall extended length (measured from tip to tip). Use a measuring tape to measure the door gas strut that you are replacing. Measure from the CENTER of the gas prop head (little plastic end), to the other side. DO NOT measure from the end of the gas prop, your measurement will be too long. Note that most applications allow for 1-5% size variation.
• These undercover bed cover shocks do not match all tonneau cover struts and are only compatible with undercover pickup bed cover. If you are not sure of the fit, measure your gas strut lift support from center of socket to center of socket when fully opened & fully closed to get accurate measurement. Please see pictures to determine how to measure gas springs. Do NOT measure from end to end. Measurement must be from the center of plastic ball mount on each end of the gas spring lift.
• Equivalent to # GPSt270P or Stabilus # 0518. Fits all SE/Classic/Elite Undercover truck bed covers except for Ford Sporttrac Undercover. Will NOT FIT ANY FIBERGLASS tonneau covers. Comes with four 10mm ball mounts for alternate 'other than truck camper shell' applications. These gas shock lift supports CANNOT be compressed by hand. They MUST be installed in the EXTENDED / OPEN position. Do NOT try to install them in the CLOSED position. Refer to the install video for guidance on how to install.
• These undercover replacement parts are compatible with undercover tonneau cover parts only! Although they may fit other brands, we have ONLY tested these undercover bed cover parts to be compatible with Undercover parts only. When you are performing an undercover lock replacement or swapping out other undercover truck bed cover parts, it's a good idea to also replace the gas support strut / tonneau cover shocks as well! These gas lift support are strong an durable, and last up to 5 years.