Cal Royal 88-VO Offset Top Arm Assembly, Surface Type

The Cal-Royal 88-VO is the "VO" type offset top arm assembly for the Cal-Royal 88 Series concealed overhead door closure. On a concealed overhead closure, the closer body is hidden inside the door's transom or header and a top arm connects it to the door, and the arm type has to match how the door is hung. The 88-VO is the offset arm, used for offset-hung doors (butt-hinge or offset-pivot applications), where the standard center-hung arms won't work. It's a single-acting offset arm sized for a 7/8" depth top rail, the genuine Cal-Royal part to specify or replace when an 88 Series closer is set up on an offset-hung door.

What the top arm assembly does and when you need the VO

This is the key thing to understand, because the arm is what makes a concealed closer fit a specific door. The 88 Series closer is concealed in the header, and the top arm transfers the closer's force to the door to swing it shut in a controlled way. Cal-Royal offers different arm types for different door-hanging methods: the S (side loading) and A, K, and PT (end loading) arms are for center-hung doors, while the JO and VO offset arms are for offset-hung doors on butt hinges or offset pivots.

So you choose the 88-VO specifically when the door is offset-hung and the application calls for the VO offset arm. It's single-acting (the door swings and closes in one direction), which is how offset-hung doors operate. Getting the arm type right is the whole point, an offset-hung door needs an offset arm, and ordering a center-hung arm by mistake means the closer won't mount or function correctly.

Genuine Cal-Royal 88 Series replacement part

The 88-VO is a genuine Cal-Royal component matched to the 88 Series closer, so it fits and functions as the closer was designed to. It's the part to order when you're specifying an 88 Series closer for an offset-hung opening (the JO and VO offset arms are optional and must be specified separately from the closer body), or when you're replacing a damaged or incorrect arm on an existing 88 Series installation. It's sized for a 7/8" depth top rail, which corresponds to the extended-spindle option in the 88 Series arm range, so confirm your door's top rail depth matches.

Using the genuine arm keeps the closer within its Grade 1 rating and original operation, which a mismatched or generic arm cannot guarantee on a concealed closer where the geometry has to be exact.

Cal-Royal 88-VO specifications

• Type: Offset top arm assembly ("VO" type), for Cal-Royal 88 Series concealed overhead door closers.

• Application: Offset-hung doors (butt-hinge or offset-pivot), single-acting.

• Top rail depth: 7/8" (extended spindle range).

• Arm family: One of the 88 Series offset arms (JO and VO), as opposed to the S/A/K/PT center-hung arms.

• Part type: Genuine Cal-Royal replacement/specified arm assembly.

• Part number: 88-VO.

Why order the genuine Cal-Royal 88-VO

For a Cal-Royal 88 Series concealed closer on an offset-hung door, the 88-VO is the correct offset top arm to make the closer work as designed. A genuine Cal-Royal arm guarantees the fit and geometry the concealed closer requires, and ordering the right arm type by door-hanging method is the most important detail on a concealed-closer job. Whether you're specifying a new 88 Series installation for an offset-hung opening or replacing an arm in the field, the 88-VO is the matched part.

One thing to confirm before ordering: the 88-VO is the offset arm for offset-hung doors, sized for a 7/8" depth top rail. Verify your door is offset-hung (not center-hung, which uses the S/A/K/PT arms) and that your top rail depth matches. If you need the mortise-type offset arm instead, the related 88-JO is the alternative offset assembly, and the closer body and bottom pivot are ordered separately.

Order the Cal-Royal 88-VO from American Locksets

We stock the Cal-Royal 88 Series concealed closer line and arms from authorized distribution, so every part ships with the manufacturer warranty. Find the closer bodies and related arms in the Cal-Royal 88 Series concealed closers category, see all overhead concealed closers, or browse all door closers.